Re: Something a little different - Car Radio question
This is not normal. I know of no normal situation where you would lose your AM reception. Sounds like the installer is tuned out. Complain to Best Buy management ASAP. Fred Townsend Charles Grasso wrote: Hello all, Well Xmas has come and gone and I got a nice new car stereo for Christmas. I dutifully went up to Best Buy - had it installed only to be informed that I can no longer receive AM. I happen to enjoy AM radio so this was a bit of a blow. I inquired as to what the possible cause might be and the answer I got was.. Some cars do this.. which is no answer at all. My car has an antenna in the windshield and the original radio worked just fine. I am a little confused soI thought I would ask the expert EMC community for ideas. ANyone want to hazard a guess as to what is going on?? Chas _ Join the worlds largest e-mail service with MSN Hotmail. http://www.hotmail.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Something a little different - Car Radio question
Some cars do this? Nonsense! As you of course know. 1. It may be that your windshield antenna will not work with the particular model radio you got, which would only mean drilling a small hole and installing a whip. You should be able to find this out by calling the manufacturer and asking. 2. Less charitably, the folks who put your radio in may have broken your windshield antenna (necessitating a replacement windshield, which they will NOT want to pay for) and are either unable to figure it out, unwilling to fix it, or are trying to force you into having a different, and more expensive, radio installed. That last is called bait and switch and borders on the criminal in most states. Some obvious reactions come to mind. Calling the national or regional Best Buys office. Calling your state's consumer protection office (they may have handled pervious complaints from this store.) Suing them repair the damage to your car. Others are probably forthcoming, here! Cortland (What I write here is mine alone. My employer does not Concur, agree or else endorse These words, their tone, or thought.) Charles Grasso wrote: Hello all, Well Xmas has come and gone and I got a nice new car stereo for Christmas. I dutifully went up to Best Buy - had it installed only to be informed that I can no longer receive AM. I happen to enjoy AM radio so this was a bit of a blow. I inquired as to what the possible cause might be and the answer I got was.. Some cars do this.. which is no answer at all. My car has an antenna in the windshield and the original radio worked just fine. I am a little confused soI thought I would ask the expert EMC community for ideas. ANyone want to hazard a guess as to what is going on?? Chas _ Join the worlds largest e-mail service with MSN Hotmail. http://www.hotmail.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I have it from a message on the r...@contesting.com list that Phillips bulbs produce less RF noise than others. I can't vouch for that, however. Cortland (What I write here is mine alone. My employer does not Concur, agree or else endorse These words, their tone, or thought.) Rich Nute wrote: I've replaced the incandescent lamp on my bedside table with a new energy-saving compact flourescent lamp. With the lamp on, I cannot listen to even the strongest AM radio station on my clock radio (on the same bedside table) due to the lamp interference. This must not be the usage contemplated by EMC requirements. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
The answer is in the original posting, the new lamp saves energy. Which translates into saving the planet. That trumps all, these days. -- From: geor...@lexmark.com To: Rich Nute ri...@sdd.hp.com Cc: j...@jmwa.demon.co.uk, emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Thu, Jan 3, 2002, 3:32 PM I think the issue is that the lamp is not an EMC regulated device. In fact, in Europe, ITE conducted emissions must be regulated so as not to cause desk/room lights to flicker, as in when a fuser lamp in a printer kicks on. Apparantly the proper functioning of lighting takes precedence over the propoer functioning of radios and the like affected by the lights? George Rich Nute richn%sdd.hp@interlock.lexmark.com on 01/03/2002 04:08:51 PM Please respond to Rich Nute richn%sdd.hp@interlock.lexmark.com To: jmw%jmwa.demon.co...@interlock.lexmark.com cc: emc-pstc%majordomo.ieee@interlock.lexmark.com (bcc: George Alspaugh/Lex/Lexmark) Subject: Re: EMC-related safety issues Hi John: I've replaced the incandescent lamp on my bedside table with a new energy-saving compact flourescent lamp. With the lamp on, I cannot listen to even the strongest AM radio station on my clock radio (on the same bedside table) due to the lamp interference. This must not be the usage contemplated by EMC requirements. Limits in the household environment are based on a 3 m separation between source and receiver. Wonderful! Either the lamp or the radio must be on the opposite side of the room from my bedside table. When I am in bed, one or the other is not controllable, and is therefore useless to me. Whine mode on: I want both on my bedside table, and I want both to do all of their functions. This IS not the usage contemplated by 3 m separation EMC requirements. :-) Best wishes for the New Year, Rich --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
Emissions from a laptop are naturally (without suppression) on the order of 10 uV/m to 100s of uV/m. 1000 uV/m would represent at least a 20 dB outage at frequencies that could possibly interfere with sensor electronics. The coupling is lossy: 1 mV/m will generate far less than 1 mV signal in the electronics, and this at rf. Does anyone really see this as a remotely possible mechanism? I don't. -- From: Robert Macy m...@california.com To: Pettit, Ghery ghery.pet...@intel.com, 'James Collum' james.col...@usa.alcatel.com, emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Thu, Jan 3, 2002, 3:25 PM Perhaps, it merely interfered with the sensor electronics, not the true magnetic field that was being sensed. - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message- From: Pettit, Ghery ghery.pet...@intel.com To: 'James Collum' james.col...@usa.alcatel.com; emc-p...@majordomo.ieee.org emc-p...@majordomo.ieee.org Date: Thursday, January 03, 2002 11:46 AM Subject: RE: EMC-related safety issues I still have a hard time believing it was a compass that was affected by a laptop computer. ADF indication, could be. VOR, maybe. Magnetic compass? I wouldn't want a magnetic source that strong in my lap! My belt buckle would be stuck to it. There is quite a distance between a magnetic compass in the cockpit of an airliner and anything a passenger is carrying. Not so in a Cessna 172, but in a DC-10? Ghery Pettit -Original Message- From: James Collum [mailto:james.col...@usa.alcatel.com] Sent: Thursday, January 03, 2002 10:47 AM To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues * A routine flight over Dallas-Fort Worth was disrupted when one of the compasses suddenly shifted 10 degrees to the right. The pilot asked if any passenger was operating an electronic device, and finding that a laptop computer had just been turned on requested that it be turned off, whereupon the compass returned to normal. Following RTCA guidelines the pilot requested that the laptop be turned on again 10 minutes later, when the compass error returned. Ref: Compliance Engineering (European edition) Nov/Dec 1996 p12 * I am fascinated by this amazing story (which must surely be an urban myth) and went in search of more info on the internet. I had never heard of the RTCA ( a private corporation) before, but noticed via their web site that you have to be a member company (i.e. pay) to receive the wisdom that it contains. Aviation is merely a hobby of mine but I'm interested in reading a copy of the RTCA's DO-233/214 and 196 documents without shelling out hundreds for the privilege, can anyone advise? Also does anyone know what recommendations have they made to modifying FAR 91.21 (as per their web site). In reading this again, I'm curious as to how the pilot would have known about a private companies convoluted guideline for fault finding on errant radio direction equipment involving locating industrious passengers and commandeering their computers at 10 minute intervals. Surely he would have done what any professional engineer would do, beat or kick the 10 degree error out of the RDF equipment? Or maybe just wonder to him/herself about how strange things happen in the Dallas Fort Worth area? Tounge in cheek, my comments and not those of my employer etc. Jim --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave
Re: EMC-related safety issues
Ken Javor wrote: Curiosity. How long must airbags work? As long as you have the car, supposedly. Same with seat belts. They're all safety features. Interestingly, if you have a cracked or broken windshield, a cop *can* write you up for the car being unsafe. I've never heard of it, but a classmate of mine who became a statie told me when he saw a huge crack in my windshield. I'm also under the impression that manufacturers are responsible for maintaining a repair/replacement parts inventory to dealers for only 10 years. Not sure about that one. - Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
Rich, I think you're right. Both lawyer and plaintiff are responsible. The jury that goes along with the whole thing just because an insurance company is going to pay the whole thing is no help either. The lady years ago (Oakland Calif if memory serves) that sued the store that sold, and the manufacturer who design, a skateboard. Seems her son fell off and broke and arm. She sued as an attractive nusiance I have fantasies of just once someone in the Jury standing up and screaning. What the heck did you expect when you bought your son a board that was mounted to little wheels lady, and then giving the plantiffs lawyer a swift kick for wasting everyones time. I have a wonderful lawyer joke, but I'll spare the group - but I'm chuckling pretty hard Gary -Original Message- From: Rich Nute [mailto:ri...@sdd.hp.com] Sent: Thursday, January 03, 2002 12:21 PM To: ken.ja...@emccompliance.com Cc: cherryclo...@aol.com; m...@california.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Hi Ken: Trial lawyers and their clients have an obvious interest in portraying consumers as helpless and child-like, and rich corporations as robber-barons preying on the poor and weak. But why does the rest of society jump on that bandwagon? Because profit and wealth, once badges of achievement, are now considered prima facie evidence of malfeasance. The trail lawyers, in an attempt to enrich themselves, have launched a full-scale attack on the system of capitalism itself. But unlike a real capitalist, who enriches himself by serving others, the trial lawyer is a parasite - he achieves his success at the expense of others, and the degree of his success is the degree of destruction visited on society. It is not the lawyers, but the client/plaintiff who sees an opportunity for a free ride for the rest of his life. Society wants to see the little guy get the free ride and the deep-pocket corporation pay through the nose for his misdeeds. I don't really believe that the client/plaintiff motive is punishment of the deep-pocket corporation, although that theory may be the one used in court. Ambulance-chasing lawyers do influence the client/ plaintiff in their path to the free ride, as the lawyers, too, want a free ride. (It seems to me that there is a prepronderance of very nice cars that bear the wheelchair symbol.) Best wishes for the New Year, Rich --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
Rich Nute wrote: EMC? Ha! You raise a good point since the FCC legally can but hasn't implemented an American version of immunity standards. The words must accept on the FCC labels of your effected devices are evident of it. Maybe some day we will have do immunity testing. - Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
Re: EMC-related safety issues I do not disagree but what about the use of mobile phones in emergencies - should the FCC require all advertisements to carry a warning that mobile phones cannot be relied upon for emergencies? I think that would be a great idea as it might even focus the minds of the service provides to provide service! : ^ ] Best regards Gregg (Kervill) -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of richwo...@tycoint.com Sent: Thursday, January 03, 2002 8:26 AM To: emc-p...@majordomo.ieee.org Subject: RE: EMC-related safety issues Ken, let me address the specific case you mentioned - the RF camera used for baby surveillance. In that particular application, surveillance for the protection of persons, more severe immunity requirements apply. Those requirements are either specified in EN 50130-4 or the particular ETSI product EMC standard. A manucturer should understand that the product may be used for protection of persons and apply the appropriate immunity requirements. Failure to do so, could create a liability issue. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, January 02, 2002 2:22 PM To: cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I have read a part of the IEE guide mentioned below. What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or misuse of the equipment he sells in concert with every other type of equipment made or that might be made at some time in the future. This document is a trial lawyer's dream. It takes us from a society in which a sale was deemed a transaction of mutual benefit between equals to a society in which an Omniscient Producer must cater to the needs of an ignorant, childlike Consumer, and in direct corollary, any misuse of any product by any consumer is deemed proof that the Omniscient Producer was profiting by taking advantage of a helpless victim. I realize this document merely reflects this prevalent view, but the idea that an Industry group would provide such a smoking gun for some trial lawyer to use in defense of some poor misled swindled consumer is, to say the least, troubling. To say that Industry standards don't go far enough, that it is the responsibility of the Producer to be able to determine all possible environments and failure modes that might ever occur is placing an impossible burden and any rationale entity, upon reading this document will immediately cease production of anything that could conceivably ever malfunction in anyway whatsoever. Case in point: A friend of mine bought one of these 2.4 GHz remote miniature video cameras with integral IREDs and is able to monitor his infant twins from his own bedroom, even in the middle of the night with no lights on in the twins' bedroom. Suppose that 2.4 GHz link is disturbed in some way and he misses something important happening in that bedroom. Is the manufacturer of that video system responsible for any ill that then befalls my friend's twins? I think not. But this safety guide says yes, and places the manufacturer at risk. -- From: cherryclo...@aol.com To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Wed, Jan 2, 2002, 9:49 AM Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it. Of course I am passionate about the IEE guide - my colleagues and I spent a long time working on it! When I discovered you were criticising it to the emc-pstc of course I had to respond - but I was not (and am not) trying to defend the guide, merely trying to find out just exactly what it is that you (and your silent 'equally senior experts') don't like about it so I can get it improved. I am sorry if my wordy emails give the wrong impression - the simple fact is that I always write too much (as any editor who has had an article from me will confirm!). Once again I ask you - and everyone else in the entire EMC or Safety community world-wide - to read the IEE's guide and let me have constructive comments about how to improve it. You can easily download it for free from www.iee.org.uk/Policy/Areas/Electro (- you only need to download the 'core' document for this exercise and can leave the nine 'industry annexes' for later criticism). I'll make it easy for anyone to comment even if they haven't read the Core of the IEE's guide ...the guide is based on the following engineering approach, explicitly stated at
Re: EMC-related safety issues
LOL. Not entirely beside the point. That rubbish attracts listeners. The more listeners, the more advertising time is worth. The less interference, the more potential listeners. Advertising revenue then depends on clear reception and no rfi. Now you have the fundamental reason for FCC/CISPR EMI control. No rubbish! -- From: John Woodgate j...@jmwa.demon.co.uk To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Thu, Jan 3, 2002, 2:20 PM I do not find that. In most US hotels I've stayed in, the bedroom radios are cheapo-squared but still receive 99 stations - all putting out rubbish, so any interference is beside the point. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
Re: EMC-related safety issuesIn Ken's second scenario, Chrysler Corp. had to fix the Dodge/Plymoth min-van's rear door latch. I'm sure of the other two. However, note that it is not the US government that would be after the knife (actually a box cutter) manufacturer, but what we call on this side of the pond, ambulace chasers, also known as lawers. Now for my Lawyer Joke - There are two kinds of lawyers. Good ones and Bad ones. And, we do not need any more of either kind. John -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of James, Chris Sent: Thursday, January 03, 2002 9:06 AM To: 'Ken Javor'; 'acar...@uk.xyratex.com'; emc-p...@majordomo.ieee.org Subject: RE: EMC-related safety issues So why ain't the US government chasing the knife manufacturer of the knives used by the terrorists rather than Bin Laden I'm sorry but stories like the below make me despair at the way society is headed. If people want technology they will have to accept some of the pitfalls that come with it, within reason, else where will it end? -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: 03 January 2002 17:00 To: James, Chris; 'acar...@uk.xyratex.com'; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I agree with what you say, but at least in this country the anti-business pendulum has swung farther than you imagine. A couple examples. Thurman Munson, a Yankee catcher in the '70s, was killed in his twin engine Cessna jet. He crashed short of a runway. His estate sued Cessna, not on the grounds that the jet was defective, but that Cessna had sold Munson more aircraft than he was capable of handling. Cessna demonstrated that it had sold Munson the model he wanted, but the plaintiff claimed that it was Cessna' duty to assess Munson's skills as a pilot and tell him, the customer, what aircraft they would sell him. I don't recall how the verdict was rendered, but I know Cessna paid something. Another case involved the death of a child in an automobile accident involving a minivan. The child was thrown from the vehicle, in part because the rear door sprang open on impact. Plaintiff claimed the door was poorly designed and that the child would have remained in the vehicle and maybe not been killed had the doors remained closed. Defendant pointed out that child was not restrained in vehicle, he was up and and about at the moment of impact. Documentation supplied with vehicle clearly states all passengers should wear restraining belts. Plaintiff countered that defendant should have known that if they built a vehicle as large as a minivan that kids would be up and about and vehicle should have been designed with that in mind. Again do not recall verdict but I am sure plaintiff did not walk away empty-handed. Agreed that a manufacturer is responsible for the safety of a product put into normal use. That was established by case law as far back as the Babylonian Code of Hammurabi, wherein an architect who builds a house that collapses and kills the owner is liable to the same fate. But the manufacturer today labors under a presumption of evil: if he makes a profit from selling a product, he must have skimped somewhere, because profits are intrinsically evil. -- From: James, Chris c...@dolby.co.uk To: 'acar...@uk.xyratex.com' acar...@uk.xyratex.com, emc-p...@majordomo.ieee.org Subject: RE: EMC-related safety issues Date: Thu, Jan 3, 2002, 8:25 AM Ken, I don't think anyone could disagree with your sentiments. The problem is attributing the level of liability between user and manufacturer. Car manufacturers sleep at night yet their products kill thousands each year, they design them to high standards yet by their use they still kill and maim. Do we hold them liable, no, in 99.9% of cases we don't. You slip down the stairs and break your leg, do you sue: a.. the caveman who invented the staircase? b.. your shoe manufacturer for using a shoe sole incompatible with the stair carpet? c.. the stair carpet manufacturer for using material incompatible with the shoe sole material? d.. the distiller for not putting a warning on the bottle of whisky you just drank It's reasonable responsibility/diligence that needs defining, not spurious emissions!! In addition the legal fraternity should have some standards imposed upon them to put an end to pure gold digging through litigation that seems to just escalate and to which we thus have to pander. If every foreseeable mis-use of every commodity sold was accounted for then no-one would sell anything. Chris __ Chris James Engineering Services Manager Dolby Laboratories, Inc. (UK) -Original Message- From:
RE: EMC-related safety issues
-Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Thursday, January 03, 2002 11:55 AM To: Cortland Richmond; Andrew Carson Cc: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Curiosity. How long must airbags work? A car can be driven for two decades or more, by an uncontrolled number of owners, and with no mandatory inspection or service. How long is a manufacturer liable for the proper operation of those airbags? Same question for anti-lock brakes. If the warning light comes on and is ignored, who is at fault? If the warning light is disabled by an owner, and the next owner suffers injury due to improper operation of either of these systems, who is at fault? Don't give me the logical answer. I can figure that out. Knowing that the culpable seller is not a tempting target but the manufacturer is, in the present climate some bright lawyer will come up with a rationale for suing the manufacturer. It is the climate that must be changed and the IEE guide that started this thread, in my opinion, appeases this trend rather than opposes it. My non-expert opinion is that warranties on systems like air-bags, anti-lock brakes and seatbelts may have the same legal obligations as the Federal requirements for (fuel) Emission controls (IIRC, 6 years or 100k miles?). Ed Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Services Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
My copy of BS EN 50140-4:1996 was 'published under the authority of the Standards Board and comes into effect on 15 August 1996.' BS DOW was 2001-01-01 for the 1998 version. Amendment 10102 dated September 1998 affects page 3, adding 'alarm transmission systems' to the scope. Comments: 1) Supersedes generic immunity requirements if product is positioned within scope EN50130-4. 2) Test conditions and acceptance criteria differ from generic immunity David -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Thursday, January 03, 2002 1:59 PM To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6ABC4FD5@flbocexu05) about 'EMC-related safety issues', on Thu, 3 Jan 2002: more severe immunity requirements apply. Those requirements are either specified in EN 50130-4 According to the BSI web site, BS EN 50130-4 is not yet published. Comments? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I think the issue is that the lamp is not an EMC regulated device. In fact, in Europe, ITE conducted emissions must be regulated so as not to cause desk/room lights to flicker, as in when a fuser lamp in a printer kicks on. Apparantly the proper functioning of lighting takes precedence over the propoer functioning of radios and the like affected by the lights? George Rich Nute richn%sdd.hp@interlock.lexmark.com on 01/03/2002 04:08:51 PM Please respond to Rich Nute richn%sdd.hp@interlock.lexmark.com To: jmw%jmwa.demon.co...@interlock.lexmark.com cc: emc-pstc%majordomo.ieee@interlock.lexmark.com (bcc: George Alspaugh/Lex/Lexmark) Subject: Re: EMC-related safety issues Hi John: I've replaced the incandescent lamp on my bedside table with a new energy-saving compact flourescent lamp. With the lamp on, I cannot listen to even the strongest AM radio station on my clock radio (on the same bedside table) due to the lamp interference. This must not be the usage contemplated by EMC requirements. Limits in the household environment are based on a 3 m separation between source and receiver. Wonderful! Either the lamp or the radio must be on the opposite side of the room from my bedside table. When I am in bed, one or the other is not controllable, and is therefore useless to me. Whine mode on: I want both on my bedside table, and I want both to do all of their functions. This IS not the usage contemplated by 3 m separation EMC requirements. :-) Best wishes for the New Year, Rich --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
Perhaps, it merely interfered with the sensor electronics, not the true magnetic field that was being sensed. - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message- From: Pettit, Ghery ghery.pet...@intel.com To: 'James Collum' james.col...@usa.alcatel.com; emc-p...@majordomo.ieee.org emc-p...@majordomo.ieee.org Date: Thursday, January 03, 2002 11:46 AM Subject: RE: EMC-related safety issues I still have a hard time believing it was a compass that was affected by a laptop computer. ADF indication, could be. VOR, maybe. Magnetic compass? I wouldn't want a magnetic source that strong in my lap! My belt buckle would be stuck to it. There is quite a distance between a magnetic compass in the cockpit of an airliner and anything a passenger is carrying. Not so in a Cessna 172, but in a DC-10? Ghery Pettit -Original Message- From: James Collum [mailto:james.col...@usa.alcatel.com] Sent: Thursday, January 03, 2002 10:47 AM To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues * A routine flight over Dallas-Fort Worth was disrupted when one of the compasses suddenly shifted 10 degrees to the right. The pilot asked if any passenger was operating an electronic device, and finding that a laptop computer had just been turned on requested that it be turned off, whereupon the compass returned to normal. Following RTCA guidelines the pilot requested that the laptop be turned on again 10 minutes later, when the compass error returned. Ref: Compliance Engineering (European edition) Nov/Dec 1996 p12 * I am fascinated by this amazing story (which must surely be an urban myth) and went in search of more info on the internet. I had never heard of the RTCA ( a private corporation) before, but noticed via their web site that you have to be a member company (i.e. pay) to receive the wisdom that it contains. Aviation is merely a hobby of mine but I'm interested in reading a copy of the RTCA's DO-233/214 and 196 documents without shelling out hundreds for the privilege, can anyone advise? Also does anyone know what recommendations have they made to modifying FAR 91.21 (as per their web site). In reading this again, I'm curious as to how the pilot would have known about a private companies convoluted guideline for fault finding on errant radio direction equipment involving locating industrious passengers and commandeering their computers at 10 minute intervals. Surely he would have done what any professional engineer would do, beat or kick the 10 degree error out of the RDF equipment? Or maybe just wonder to him/herself about how strange things happen in the Dallas Fort Worth area? Tounge in cheek, my comments and not those of my employer etc. Jim --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
Hi John: I've replaced the incandescent lamp on my bedside table with a new energy-saving compact flourescent lamp. With the lamp on, I cannot listen to even the strongest AM radio station on my clock radio (on the same bedside table) due to the lamp interference. This must not be the usage contemplated by EMC requirements. Limits in the household environment are based on a 3 m separation between source and receiver. Wonderful! Either the lamp or the radio must be on the opposite side of the room from my bedside table. When I am in bed, one or the other is not controllable, and is therefore useless to me. Whine mode on: I want both on my bedside table, and I want both to do all of their functions. This IS not the usage contemplated by 3 m separation EMC requirements. :-) Best wishes for the New Year, Rich --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Something a little different - Car Radio question
Hello all, Well Xmas has come and gone and I got a nice new car stereo for Christmas. I dutifully went up to Best Buy - had it installed only to be informed that I can no longer receive AM. I happen to enjoy AM radio so this was a bit of a blow. I inquired as to what the possible cause might be and the answer I got was.. Some cars do this.. which is no answer at all. My car has an antenna in the windshield and the original radio worked just fine. I am a little confused soI thought I would ask the expert EMC community for ideas. ANyone want to hazard a guess as to what is going on?? Chas _ Join the worlds largest e-mail service with MSN Hotmail. http://www.hotmail.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Re: Electric Shock and Water
Rich Do you use Google.com for searches. I did a search on water conductivity yesterday and got a lot of hits with typical values. Many related to biological studies. See, for example http://www.dartmouth.edu/~bio59/conductivity.htm -Jason Rich Nute ri...@sdd.hp.com wrote: Hi John: Is there a value (or range of values) for the resistance of water? The data exists; it depends, of course, on solute nature and concentration. Try a web search. I did a web search before my post. There is lots of data on the use of water resistance and water conductivity, but I found nothing on the values of water resistance or water conductivity. Somewhere in yesterday's web search, I recall having seen a reference to DI water has being 18 megohms maximum, and ordinary water being in the neighborhood of 2 kilohms. But, neither of these values was well-documented, and questionable as to applicability to the question at hand, so I did not quote them. I did another search today. Water conductivity measurements are used to estimate the total dissolved salts (TDS) in the water. This site explains TDS and gives conductivity values for various lakes: http://wow.nrri.umn.edu/wow/under/parameters/conductivity.html (The last two paragraphs of this URL are recommended reading.) This URL has lake and ocean water ranging from 100,000 ohms to 23 ohms and even 6 ohms. I found a water conductivity meter that measures up to 1999 milliSiemens. This would correspond to 0.5 ohm. This would imply the resistance of water would range from infinite to something on the order of 50 ohms (assuming the meter range would exceed the expected values by 100X). Perhaps this meter is a conductivity cell, but the specs do not describe it as such. http://www.sentry-products.co.uk/Products/Water%20Conductivity%20Meters$20Body.htm I find it disturbing that the web does not have more published values for water conductivity. I wonder if this is because there are no standard values for water resistance? I suspect that the values are completely variable and unpredictable. I would think that water supply authorities would publish EC and TDS of the water supplied to customers as these are measures of water hardness. Is there a standard way of measuring the resistance of water? Yes; a conductivity cell. An apparently simple device that isn't. Once again, a web search will probably disclose more than you ever wanted to know. Using your suggestion, I did a search and found limited (not more than I ever wanted to know) information on the conductivity cell: http://www.ussl.ars.usda.gov/answers/mc0.htm http://www.thermo.com/eThermo/CDA/Products/Product_Listing/0,1086,107687-161-161,00.html The first URL explains the theory of operation in general terms. The second URL is a manufacturer of conductivity cells. Best regards, Rich --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. -- __ Your favorite stores, helpful shopping tools and great gift ideas. Experience the convenience of buying online with Shop@Netscape! http://shopnow.netscape.com/ Get your own FREE, personal Netscape Mail account today at http://webmail.netscape.com/ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Lasting of the CE marking
Hi all I was just seeking through EMC LVD RTTE and MD directives for evidence of my interpretation but I couldn't find it, so can some of you help me. As I recall there are the following rules: For EMC directive you will always have to produce according to the latest harmonized standards (after dow date) For all other directives you just use the harmonized standards which was acceptable at the time of entry to the market (then you can produce the same product for decades without retesting to new harmonized standards) Please help me finding the clauses in the directives which supports this statement. But what about RTTE when new standards are harmonized where no standards was before ? Best regards, Kim Boll Jensen Bolls Raadgivning attachment: kimboll.vcf
RE: Touch-Pad ESD immunity
-Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Wednesday, January 02, 2002 8:34 PM To: emc-p...@majordomo.ieee.org Subject: Re: Touch-Pad ESD immunity I read in !emc-pstc that Gary McInturff Gary.McInturff@worldwidepackets .com wrote (in 917063bab0ddb043af5faa73c7a835d40c0...@windlord.wwp.com ) about 'Touch-Pad ESD immunity', on Wed, 2 Jan 2002: Do you have denounce circuitry on the input of the touch pad The spell-checker demon strikes again! (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. Too long of a holiday, as I'm starting the new year with insufficient alphabetical noise immunity! I actually did a Google search on denounce circuitry. Ed Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military Avionics EMC Services Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
Hello John, If the BSI site says that, then it is yet another proof of you can't always believe what you read. :) My Aug 2001 version of the BSI electronic catalog shows a publication date of 1996 for the BS EN ( but the document was actually released in late 1995) with an addendum A1 published in 1998. The hard copy sitting in front of me (from BSI) agrees with the electronic catalog :) There was a very generous transition period which ended in January of 2001. Best Regards, Kevin Harris Manager, Approval Services Digital Security Controls 3301 Langstaff Road Concord, Ontario CANADA L4K 4L2 Tel: +1 905 760 3000 Ext. 2378 Fax +1 905 760 3020 Email: harr...@dscltd.com -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Thursday, January 03, 2002 1:59 PM To: emc-p...@majordomo.ieee.org Subject:Re: EMC-related safety issues I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6ABC4FD5@flbocexu05) about 'EMC-related safety issues', on Thu, 3 Jan 2002: more severe immunity requirements apply. Those requirements are either specified in EN 50130-4 According to the BSI web site, BS EN 50130-4 is not yet published. Comments? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
Hi Ken: Trial lawyers and their clients have an obvious interest in portraying consumers as helpless and child-like, and rich corporations as robber-barons preying on the poor and weak. But why does the rest of society jump on that bandwagon? Because profit and wealth, once badges of achievement, are now considered prima facie evidence of malfeasance. The trail lawyers, in an attempt to enrich themselves, have launched a full-scale attack on the system of capitalism itself. But unlike a real capitalist, who enriches himself by serving others, the trial lawyer is a parasite - he achieves his success at the expense of others, and the degree of his success is the degree of destruction visited on society. It is not the lawyers, but the client/plaintiff who sees an opportunity for a free ride for the rest of his life. Society wants to see the little guy get the free ride and the deep-pocket corporation pay through the nose for his misdeeds. I don't really believe that the client/plaintiff motive is punishment of the deep-pocket corporation, although that theory may be the one used in court. Ambulance-chasing lawyers do influence the client/ plaintiff in their path to the free ride, as the lawyers, too, want a free ride. (It seems to me that there is a prepronderance of very nice cars that bear the wheelchair symbol.) Best wishes for the New Year, Rich --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 200201031919.laa11...@epgc264.sdd.hp.com) about 'EMC-related safety issues', on Thu, 3 Jan 2002: I've replaced the incandescent lamp on my bedside table with a new energy-saving compact flourescent lamp. With the lamp on, I cannot listen to even the strongest AM radio station on my clock radio (on the same bedside table) due to the lamp interference. This must not be the usage contemplated by EMC requirements. Limits in the household environment are based on a 3 m separation between source and receiver. My TV and stereo are more-or-less integrated (they are in close proximity). On New Year's Day, I wanted to listen to the radio version of the football game description while watching the TV. With the TV on, I cannot listen to even the strongest AM radio station due to the TV interference. This must not be the usage contemplated by EMC requirements. See above. I take my Grundig portable radio with me when I travel. Most hotels have sufficient interference sources that I cannot listen to AM radio, and sometimes not even FM radio (with lights and TV off!). This must not be the usage contemplated by EMC requirements. I do not find that. In most US hotels I've stayed in, the bedroom radios are cheapo-squared but still receive 99 stations - all putting out rubbish, so any interference is beside the point. But at least the bedroom radios have an antenna system. It is not surprising that you cannot get good reception on built-in antennas in steel-framed buildings. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I read in !emc-pstc that John Shinn john.sh...@sanmina-sci.com wrote (in 00c001c1948d$a53fb580$0b3d1...@hadco.comsanmina.com) about 'EMC- related safety issues', on Thu, 3 Jan 2002: NO NO NO. Don't think about the plane. There will be more red tape than you want to think about, especially if it is bolted down (permanently installed). If not approved by the appropriate government agency (the FAA's FSDO - Flight Safety District Office), it could cause loss of airworthyness of the aircraft. Even more problems if you have to punch a hole in the skin. But, just from the paperwork issue, don't go there. I don't actually have a plane, but the camera manufacturer doesn't know that, so in the present circumstances he must assume that I do! I'll mount it on my hydrogen balloon instead.(;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I don't understand the part I snipped. Isn't that what immunity/susceptibility testing is all about? We already do that. The part I had a problem with was the statement that industry standards are not enough, we must try to anticipate all problems that might ever arise, in effect forcing the manufacturer to have god-like omniscience, and when he predictably fails, punishing him for not living up to our preconceived notions of how smart he should have been. -- From: Rich Nute ri...@sdd.hp.com To: ken.ja...@emccompliance.com Cc: geor...@lexmark.com, emc-p...@ieee.org Subject: Re: EMC-related safety issues Date: Thu, Jan 3, 2002, 1:55 PM Today, we simply don't have processes by which we can test equipment for RF-induced bad experiences. So, we argue both sides without a conclusion. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
Hi Ken: The Forrestal incident occurred during the Vietnam conflict, July 1967. It was pretty much as you describe except I would not say EMI was not controlled. All DOD services had EMI requirements at his time. In fact, 1967 was the year that MIL-STD-461 was adopted as a Tri-Service requirement superseding Service-unique standards. The actual mechanism was that a shield termination on a pyro actuation circuit on one fighter was degraded or broken and radar illumination of it fired a weapon inadvertently, into another fully loaded, and fully fueled fighter. That was the cause of the disaster. In September 1967, MIL-E-6051C, Aircraft EMC was updated to the D revision. In D, for the first time you have 20 dB safety margin demonstration on pyro electrical actuation. Coincidence? A colleague once said: Safety standards are the inversion of bad experiences. Your story confirms this approach to safety. For commercial aircraft, especially since September 11, we can also say: Security standards are the inversion of bad experiences. The trick, of course, is to anticipate the bad experience so as to prevent it in the first place. FMEA (Failure Mode and Effects Analysis) and FTA (Fault Tree Analysis) are two process by which some specific bad experiences can be anticipated. We don't have a process by which all possible bad experiences can be anticipated. Speculation as to either the bad experience itself or the probability of the bad experience is often pooh-poohed by those who would either implement the fix or authorize implementation of the fix. In the absence of data, prevention of a speculated bad experience is unlikely, no matter the ultimate validity of the speculation. As I recall, the issue of this thread is that of anticipation of an RF signal causing a bad experience by mal-operation (not a mal-function) of an equipment. Today, we simply don't have processes by which we can test equipment for RF-induced bad experiences. So, we argue both sides without a conclusion. Hopefully, through such arguments, some of us may get an idea of how such anticipation can be implemented. Best regards, Rich --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
Curiosity. How long must airbags work? A car can be driven for two decades or more, by an uncontrolled number of owners, and with no mandatory inspection or service. How long is a manufacturer liable for the proper operation of those airbags? Same question for anti-lock brakes. If the warning light comes on and is ignored, who is at fault? If the warning light is disabled by an owner, and the next owner suffers injury due to improper operation of either of these systems, who is at fault? Don't give me the logical answer. I can figure that out. Knowing that the culpable seller is not a tempting target but the manufacturer is, in the present climate some bright lawyer will come up with a rationale for suing the manufacturer. It is the climate that must be changed and the IEE guide that started this thread, in my opinion, appeases this trend rather than opposes it. -- From: Cortland Richmond cortland.richm...@alcatel.com To: Andrew Carson acar...@uk.xyratex.com Cc: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Thu, Jan 3, 2002, 12:22 PM As engineers, we should consider the safety implications of what we design, test or otherwise work on. EMI is part of that. What is considered a safety risk depends a great deal on corporate policy, the legal, political and popular climate in one's state of residence, and the kind of equipment under consideration. As it happens, the issue of pacemaker vulnerability is addressed in more regulations than USC 47. That is why, in the United States, we have not only a limit on microwave oven leakage, but also pacemaker warning signs on microwave ovens used by the public. The robotic arm is a great example. Others are automotive airbags, or electronically controlled brakes. These sort of things are the reason why industry associations develop limits of their own. Those limits accommodate both a performance requirement and practical aspects; they can't make the product too expensive to build or no one will be able to sell them at a profit. They can't be unreliable in the field or people won't buy them at all. And they can't cause too many problems, or the company will be sued. One factor weighs against another. We are at the balance point. Regards, Cortland Richmond (What I write here is mine alone. My employer does not Concur, agree or else endorse These words, their tone, or thought.) Andrew Carson wrote: I get the idea that we a missing the whole point of this discussion. Should we as Professional Safety Engineers and Product designers consider the safety implications of EMC emissions ? The answer is a definite Yes. We have a clear duty of care and responsibility to consider all implications of our products being used in there intended application. Even if the consideration on EMC emissions and safety is Do not be silly. We still have to at least consider it. ... --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
NO NO NO. Don't think about the plane. There will be more red tape than you want to think about, especially if it is bolted down (permanently installed). If not approved by the appropriate government agency (the FAA's FSDO - Flight Safety District Office), it could cause loss of airworthyness of the aircraft. Even more problems if you have to punch a hole in the skin. But, just from the paperwork issue, don't go there. John -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of John Woodgate Sent: Thursday, January 03, 2002 8:12 AM To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6ABC4FD5@flbocexu05) about 'EMC-related safety issues', on Thu, 3 Jan 2002: Ken, let me address the specific case you mentioned - the RF camera used for baby surveillance. In that particular application, surveillance for the protection of persons, more severe immunity requirements apply. Those requirements are either specified in EN 50130-4 or the particular ETSI product EMC standard. A manucturer should understand that the product may be used for protection of persons and apply the appropriate immunity requirements. Failure to do so, could create a liability issue. But that standard is INTENDED to apply to security and crowd-control cameras in stores, places of public assembly and sheltered accommodation. To 'read it on' to a simple camera used as a sophisticated baby alarm (on the grounds that it is a 'social alarm' application) is just the sort of man-trap that has many of us very concerned indeed. I'm going to get one of those cameras and mount it in my car. Now it has to meet automotive immunity requirements. Has the manufacturer thought of that? If the car camera works, I'll put two more in my boat and plane. No doubt that has been taken into account as well.(;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
Trial lawyers and their clients have an obvious interest in portraying consumers as helpless and child-like, and rich corporations as robber-barons preying on the poor and weak. But why does the rest of society jump on that bandwagon? Because profit and wealth, once badges of achievement, are now considered prima facie evidence of malfeasance. The trail lawyers, in an attempt to enrich themselves, have launched a full-scale attack on the system of capitalism itself. But unlike a real capitalist, who enriches himself by serving others, the trial lawyer is a parasite - he achieves his success at the expense of others, and the degree of his success is the degree of destruction visited on society. -- From: cherryclo...@aol.com To: m...@california.com, emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Thu, Jan 3, 2002, 8:30 AM The general impression in Europe is that the 'culture of blame' began in the USA, leading to such warning messages as Do not use this appliance to dry pet animals on microwave ovens. It often seems that legal trends begin in the States and take about 10 years to get over to Europe. It seems a pity that the liability laws have got themselves into this state, but it was not my doing anyway and maybe some manufacturers did need to improve their attitude towards the safety of their customers (I'm thinking here of exploding Ford Pintos and similar products) so maybe it is not all bad news. Regards, Keith Armstrong In a message dated 03/01/02 05:33:20 GMT Standard Time, m...@california.com writes: Subj:Re: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date:03/01/02 05:33:20 GMT Standard Time From:m...@california.com (Robert Macy) Sender:owner-emc-p...@majordomo.ieee.org Reply-to: m...@california.com mailto:m...@california.com (Robert Macy) To:gary.mcintu...@worldwidepackets.com (Gary McInturff), ken.ja...@emccompliance.com (Ken Javor), cherryclo...@aol.com Great, Now we have to start adding information on the sales brochure, like As the purchaser of this product places this product into service said purchase is forming a licensed arrangement with the vendor to not hold said vendor culpable for all uses and potential misuses of this product You get the drift, just copy the MS licensing language on all software. - Robert - Robert A. Macy, PEm...@california.com mailto:m...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message- From: Gary McInturff gary.mcintu...@worldwidepackets.com mailto:gary.mcintu...@worldwidepackets.com To: Ken Javor ken.ja...@emccompliance.com mailto:ken.ja...@emccompliance.com ; cherryclo...@aol.com mailto:cherryclo...@aol.com cherryclo...@aol.com mailto:cherryclo...@aol.com ; emc-p...@majordomo.ieee.org mailto:emc-p...@majordomo.ieee.org emc-p...@majordomo.ieee.org mailto:emc-p...@majordomo.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Wednesday, January 02, 2002 2:38 PM Subject: RE: EMC-related safety issues Did the camera have proximal cause to the event that befell the child, well not unless it fell of of the ceiling or the tripod fell over and hit the infant, or the camera overheated and started a fire. Other than that the Lawyers need to dig their heads out - juries as well. They are just trying to chase the money. Cameras don't cause disease likes SIDS. They don't cause buildings to collapse, or burglaries or whatever else might befall the baby They are just a convenience. If they an additional input path to the parents may stop, but the actual monitoring (or the failure of monitoring) neither helped or hindered the health of the child. The camera manufacturer, even if this is sold as a baby monitor, I can't see how holding the camera manufacturer responsible can even be considered, except that it gives the lawyers somebody to sue with some money. I suppose it might give t! he parents a misplaced sense of (and I hate this word) closure because they can blame some body, rather than just life, fate, or whatever. I don't doubt your statement that somebody is trying to hold the manufacturer responsible, I just point out that it is asinine and in my opinion inexcusable to do so. Recorded history doesn't show a huge plethora of infant deaths because parents weren't able to have a video camera in the room. Gary -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, January 02, 2002 11:22 AM To: cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I have read a part of the IEE guide mentioned below. What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or
Re: EMC-related safety issues
Rich, Your scenarios are excellent at proving my point that it is largely the unregulated devices amongst us that are the true source of EMIC, i.e. electromagnetic incompatibility. Thanks, George Rich Nute richn%sdd.hp@interlock.lexmark.com on 01/03/2002 02:19:38 PM To: George_Alspaugh/Lex/Lexmark.LEXMARK@sweeper.lex.lexmark.com cc: emc-pstc%ieee@interlock.lexmark.com (bcc: George Alspaugh/Lex/Lexmark) Subject: Re: EMC-related safety issues Hi George: The key word in EMC is compatibility. This implies that electrical and electronic equipment are (ideally) designed so that each can operate normally in the presence of another. This requires limiting both the emissions and sensitivity of such devices. EMC? Ha! I've replaced the incandescent lamp on my bedside table with a new energy-saving compact flourescent lamp. With the lamp on, I cannot listen to even the strongest AM radio station on my clock radio (on the same bedside table) due to the lamp interference. This must not be the usage contemplated by EMC requirements. My TV and stereo are more-or-less integrated (they are in close proximity). On New Year's Day, I wanted to listen to the radio version of the football game description while watching the TV. With the TV on, I cannot listen to even the strongest AM radio station due to the TV interference. This must not be the usage contemplated by EMC requirements. I take my Grundig portable radio with me when I travel. Most hotels have sufficient interference sources that I cannot listen to AM radio, and sometimes not even FM radio (with lights and TV off!). This must not be the usage contemplated by EMC requirements. EMC? Ha! Rich --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
My understanding is the manufacturer must consider all reasonable uses and misuses of the product and then take the appropriate actions to ensure the safe use of the product. Warnings may form part of that action and may include a list of intended uses and warnings against other uses. However, warnings cannot replace sound engineering practice. I can sell a CCTV camera intended for QA surveillance on a factory floor and use the standard immunity levels; but if I also sell the camera in the local DIY store, then I am obviously foreseeing other uses and warnings not to use the camera in the home would be useless. Reason has to prevail. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Enci [mailto:e...@cinepower.com] Sent: Thursday, January 03, 2002 11:20 AM To: emc-p...@majordomo.ieee.org Subject: RE: EMC-related safety issues I understand in this particular case the RF camera may have been marketed for baby surveillance. The majority of camera systems, wired and wireless, that I have seen are not marketed in this manner. Most are advertised as security/surveillance cameras. Are you implying that all manufacturers of these camera systems must consider the possible use of the products for the protection of persons? What if the manufacturer clearly states in the user instructions that the product is not suitable for the protection of persons? I have always understood that a manufacturer can meet obligations by addressing intended use only. For example if I was to manufacture a kettle, I would state for boiling water only in the relevant documentation. Some of the recent messages in this thread would seem to imply that I would have to consider the possible use of the kettle being used to boil something other than water, gasoline for example. Am I then liable from the damages resulting from the possible ignition of the volatile fumes from some undefined energy source, i.e. lack of emc immunity? Enci At 08:26 03/01/02 -0500, Richard Woods wrote: Ken, let me address the specific case you mentioned - the RF camera used for baby surveillance. In that particular application, surveillance for the protection of persons, more severe immunity requirements apply. Those requirements are either specified in EN 50130-4 or the particular ETSI product EMC standard. A manucturer should understand that the product may be used for protection of persons and apply the appropriate immunity requirements. Failure to do so, could create a liability issue. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Ken Javor[mailto:ken.ja...@emccompliance.com] Sent: Wednesday, January 02,2002 2:22 PM To: cherryclo...@aol.com;emc-p...@majordomo.ieee.org Subject: Re: EMC-related safetyissues To say that Industrystandards don't go far enough, that it is the responsibility of the Producerto be able to determine all possible environments and failure modes that mightever occur is placing an impossible burden and any rationale entity, uponreading this document will immediately cease production of anything that couldconceivably ever malfunction in anyway whatsoever. But this safety guide saysyes, and places the manufacturer at risk. -- From:cherryclo...@aol.com To: emc-p...@majordomo.ieee.org Subject: Re:EMC-related safety issues Date: Wed, Jan 2, 2002, 9:49 AM Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it. Of course I am passionate about the IEE guide - my colleagues and I spent a long time working on it! When I discovered you were criticising it to the emc-pstc of course I had to respond - but I was not (and am not) trying to defend the guide, merely trying to find out just exactly what it is that you (and your silent 'equally senior experts') don't like about it so I can get it improved. I am sorry if my wordy emails give the wrong impression - the simple fact is that I always write too much (as any editor who has had an article from me will confirm!). Once again I ask you - and everyone else in the entire EMC or Safety community world-wide - to read the IEE's guide and let me have constructive comments about how to improve it. You can easily download it for free from www.iee.org.uk/Policy/Areas/Electro (- you only need to download the 'core' document for this exercise and can leave the nine 'industry annexes' for later criticism). I'll make it easy for anyone to comment even if they haven't read the Core of the IEE's guide ...the guide is based on the following engineering approach, explicitly stated at the start of its Section 4 and duplicated below. * To
Re: EMC-related safety issues
Hi George: The key word in EMC is compatibility. This implies that electrical and electronic equipment are (ideally) designed so that each can operate normally in the presence of another. This requires limiting both the emissions and sensitivity of such devices. EMC? Ha! I've replaced the incandescent lamp on my bedside table with a new energy-saving compact flourescent lamp. With the lamp on, I cannot listen to even the strongest AM radio station on my clock radio (on the same bedside table) due to the lamp interference. This must not be the usage contemplated by EMC requirements. My TV and stereo are more-or-less integrated (they are in close proximity). On New Year's Day, I wanted to listen to the radio version of the football game description while watching the TV. With the TV on, I cannot listen to even the strongest AM radio station due to the TV interference. This must not be the usage contemplated by EMC requirements. I take my Grundig portable radio with me when I travel. Most hotels have sufficient interference sources that I cannot listen to AM radio, and sometimes not even FM radio (with lights and TV off!). This must not be the usage contemplated by EMC requirements. EMC? Ha! Rich --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
John: Perhaps you should rephrase that! EMC IS a controversial issue. SAFETY IS a controversial issue. thus EMC and SAFETY ARE a controversial issue. Just my $0.02 worth. John -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of John Woodgate Sent: Thursday, January 03, 2002 8:17 AM To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I read in !emc-pstc that cherryclo...@aol.com wrote (in e5.11a0fabe.296 5d...@aol.com) about 'EMC-related safety issues', on Thu, 3 Jan 2002: Over the course of this correspondence (and in earlier postings to emc-pstc) you have cast doubt on the IEE's guide to EMC and Functional Safety without being in any way specific. No, Keith, as far as I know I have not done that. All my remarks were, or were intended to be, in reference to IEC work. But I agree that the matter has moved on. At least I hope that we can now agree that EMC and safety IS a controversial issue! -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
I still have a hard time believing it was a compass that was affected by a laptop computer. ADF indication, could be. VOR, maybe. Magnetic compass? I wouldn't want a magnetic source that strong in my lap! My belt buckle would be stuck to it. There is quite a distance between a magnetic compass in the cockpit of an airliner and anything a passenger is carrying. Not so in a Cessna 172, but in a DC-10? Ghery Pettit -Original Message- From: James Collum [mailto:james.col...@usa.alcatel.com] Sent: Thursday, January 03, 2002 10:47 AM To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues * A routine flight over Dallas-Fort Worth was disrupted when one of the compasses suddenly shifted 10 degrees to the right. The pilot asked if any passenger was operating an electronic device, and finding that a laptop computer had just been turned on requested that it be turned off, whereupon the compass returned to normal. Following RTCA guidelines the pilot requested that the laptop be turned on again 10 minutes later, when the compass error returned. Ref: Compliance Engineering (European edition) Nov/Dec 1996 p12 * I am fascinated by this amazing story (which must surely be an urban myth) and went in search of more info on the internet. I had never heard of the RTCA ( a private corporation) before, but noticed via their web site that you have to be a member company (i.e. pay) to receive the wisdom that it contains. Aviation is merely a hobby of mine but I'm interested in reading a copy of the RTCA's DO-233/214 and 196 documents without shelling out hundreds for the privilege, can anyone advise? Also does anyone know what recommendations have they made to modifying FAR 91.21 (as per their web site). In reading this again, I'm curious as to how the pilot would have known about a private companies convoluted guideline for fault finding on errant radio direction equipment involving locating industrious passengers and commandeering their computers at 10 minute intervals. Surely he would have done what any professional engineer would do, beat or kick the 10 degree error out of the RDF equipment? Or maybe just wonder to him/herself about how strange things happen in the Dallas Fort Worth area? Tounge in cheek, my comments and not those of my employer etc. Jim
Re: EMC-related safety issues
The Forrestal incident occurred during the Vietnam conflict, July 1967. It was pretty much as you describe except I would not say EMI was not controlled. All DOD services had EMI requirements at his time. In fact, 1967 was the year that MIL-STD-461 was adopted as a Tri-Service requirement superseding Service-unique standards. The actual mechanism was that a shield termination on a pyro actuation circuit on one fighter was degraded or broken and radar illumination of it fired a weapon inadvertently, into another fully loaded, and fully fueled fighter. That was the cause of the disaster. In September 1967, MIL-E-6051C, Aircraft EMC was updated to the D revision. In D, for the first time you have 20 dB safety margin demonstration on pyro electrical actuation. Coincidence? -- From: geor...@lexmark.com To: emc-p...@ieee.org Subject: EMC-related safety issues Date: Thu, Jan 3, 2002, 9:57 AM The key word in EMC is compatibility. This implies that electrical and electronic equipment are (ideally) designed so that each can operate normally in the presence of another. This requires limiting both the emissions and sensitivity of such devices. Historically, only a limited number of product types have been subject to EMC limits. Most EMC requirements are based on the assumption that the emission of specific frequencies is more likely to interfere with other equipment than white or broad spectrum emissions. For example, the FCC rules apply to devices using clocked frequencies of 10K and above, but place no limits on vacuum cleaners, blenders, arc welders, etc. unless they contain clocked electronics. The exclusion of so many products from emission/susceptibility requirements is often the cause of EMC related accidents. Some years ago, in one of the U.S. Southwestern states, the local public safety (police/fire/etc) communications were often disrupted by an unknown source. The source was eventually traced to a pin ball machine in a roadside tavern. The owner was told he must get rid of the machine. A few weeks later, the noise re-appeared. It turned out that the same pinball machine was placed in service at another pub in the county. In some cases, the interaction of two devices is not exactly foreseeable. We once received reports of one of our typewriters typing occasionally without human assistance. It turned out that the typewriter was in use fairly close to an airport radar beacon. When the radar beam swept the area of the typewriter installation, it could cause the capacitor coupled keyboard to create false keystrokes. We added a large grounded template to cover most of the interior keypad area, to increase its immunity. There can be, and have been, safety related consequences of EM incompatibility. In the 1980's (as I recall) a U.S. aircraft carrier suffered a major EMC disaster. The powerful on-board electronics, particularly the radar units, triggered the launch of a missle from one of the on-deck planes. The missle struck the bridge tower, resulting in a fire costing millions of dollars in repairs and the loss of some lives. I cannot find my copy of this event, reported some years ago in one of the electronics magazines. In general, Navies are far more sensitive to EMI due to the concentration of on- board electronics. As a result, the U.S. Navy version of the Blackhawk helicopter had few EMI problems, while the Army version had several early crashes due to interference from nearby radio stations. The moral, if there is one, is that emissions and susceptibility of unregulated devices is more often the problem than the emissions or susceptibility of a regulated device. George Alspaugh Lexmark International --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:
Re: EMC-related safety issues
I read in !emc-pstc that Gary McInturff Gary.McInturff@worldwidepackets .com wrote (in 917063bab0ddb043af5faa73c7a835d40ac...@windlord.wwp.com ) about 'EMC-related safety issues', on Thu, 3 Jan 2002: While I take your point - I'll challenge with the equally valid argument that says show me the data that they do cause SIDS! Out of order! That's the whole point! Manufacturers are being required to prepare to prove a negative, which is inherently impossible in most cases. No-one is required to prove a positive, which is easy if it is true. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6ABC4FD5@flbocexu05) about 'EMC-related safety issues', on Thu, 3 Jan 2002: more severe immunity requirements apply. Those requirements are either specified in EN 50130-4 According to the BSI web site, BS EN 50130-4 is not yet published. Comments? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
As I said in earlier posting, ADF might be used to get a bearing to a known transmitter, and thus line up an approach, but it is not IFR and cannot be used as the sole source of information in order to make a safe landing. My experience is with transport, not general aviation class aircraft. On transports, the ADF loop is too far away from any passenger-carried equipment to cause a problem. In principle, it would be easy to bank an aircraft via rfi. All that is needed is that the aircraft be on auto-pilot and the auto-pilot is responding to ground-based navigation transmissions for position information. That is what happened to that storied DC-10. -- From: Cortland Richmond cortland.richm...@alcatel.com To: Ken Javor ken.ja...@emccompliance.com Cc: Mike Hopkins mhopk...@thermokeytek.com, cherryclo...@aol.com, emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Thu, Jan 3, 2002, 11:40 AM I'm old enough, Ken, to remember ADF approaches! But laptop switchers often operate inband to frequencies used by aviation non-directional beacons. This makes them more of a threat than the harmonics from lower-frequency ones. It is also, of course, possible for the laptop's other emissions to interfere with an ILS or VOR receiver. Some of the complaints I've seen have not been rationally explicable, however. For example, at one of my former employer's (no longer in existence) a report was received that a laptop caused an aircraft to bank two degrees. I've worked with aircraft stabilization systems, and I've yet to figure out a mechanism how that could happen. Cortland (What I write here is mine alone. My employer does not Concur, agree or else endorse These words, their tone, or thought.) Ken Javor wrote: In my experience it is EXTREMELY unlikely that personal electronics could have disturbed ADF heading indication. The ADF sensor is an electrostatically shielded loop which is mounted typically on the belly of a transport class aircraft, well away from any passenger-conveyed intense sources of magnetic fields. The loop is very insensitive and requires quite a bit of magnetic field to respond and is completely insensitive to electric fields altogether. Further, no one would use ADF to line up an approach on a runway. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
CEN Standards free on-line
According to this press release, CEN standards should now be on line for free. http://europa.eu.int/rapid/start/cgi/guesten.ksh?p_action.gettxt=gtdoc=IP/0 1/1837|0|RAPIDlg=EN Richard Woods Sensormatic Electronics Tyco International --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
* A routine flight over Dallas-Fort Worth was disrupted when one of the compasses suddenly shifted 10 degrees to the right. The pilot asked if any passenger was operating an electronic device, and finding that a laptop computer had just been turned on requested that it be turned off, whereupon the compass returned to normal. Following RTCA guidelines the pilot requested that the laptop be turned on again 10 minutes later, when the compass error returned. Ref: Compliance Engineering (European edition) Nov/Dec 1996 p12 * I am fascinated by this amazing story (which must surely be an urban myth) and went in search of more info on the internet. I had never heard of the RTCA ( a private corporation) before, but noticed via their web site that you have to be a member company (i.e. pay) to receive the wisdom that it contains. Aviation is merely a hobby of mine but I'm interested in reading a copy of the RTCA's DO-233/214 and 196 documents without shelling out hundreds for the privilege, can anyone advise? Also does anyone know what recommendations have they made to modifying FAR 91.21 (as per their web site). In reading this again, I'm curious as to how the pilot would have known about a private companies convoluted guideline for fault finding on errant radio direction equipment involving locating industrious passengers and commandeering their computers at 10 minute intervals. Surely he would have done what any professional engineer would do, beat or kick the 10 degree error out of the RDF equipment? Or maybe just wonder to him/herself about how strange things happen in the Dallas Fort Worth area? Tounge in cheek, my comments and not those of my employer etc. Jim
Re: Electric Shock and Water
Hi John: Is there a value (or range of values) for the resistance of water? The data exists; it depends, of course, on solute nature and concentration. Try a web search. I did a web search before my post. There is lots of data on the use of water resistance and water conductivity, but I found nothing on the values of water resistance or water conductivity. Somewhere in yesterday's web search, I recall having seen a reference to DI water has being 18 megohms maximum, and ordinary water being in the neighborhood of 2 kilohms. But, neither of these values was well-documented, and questionable as to applicability to the question at hand, so I did not quote them. I did another search today. Water conductivity measurements are used to estimate the total dissolved salts (TDS) in the water. This site explains TDS and gives conductivity values for various lakes: http://wow.nrri.umn.edu/wow/under/parameters/conductivity.html (The last two paragraphs of this URL are recommended reading.) This URL has lake and ocean water ranging from 100,000 ohms to 23 ohms and even 6 ohms. I found a water conductivity meter that measures up to 1999 milliSiemens. This would correspond to 0.5 ohm. This would imply the resistance of water would range from infinite to something on the order of 50 ohms (assuming the meter range would exceed the expected values by 100X). Perhaps this meter is a conductivity cell, but the specs do not describe it as such. http://www.sentry-products.co.uk/Products/Water%20Conductivity%20Meters$20Body.htm I find it disturbing that the web does not have more published values for water conductivity. I wonder if this is because there are no standard values for water resistance? I suspect that the values are completely variable and unpredictable. I would think that water supply authorities would publish EC and TDS of the water supplied to customers as these are measures of water hardness. Is there a standard way of measuring the resistance of water? Yes; a conductivity cell. An apparently simple device that isn't. Once again, a web search will probably disclose more than you ever wanted to know. Using your suggestion, I did a search and found limited (not more than I ever wanted to know) information on the conductivity cell: http://www.ussl.ars.usda.gov/answers/mc0.htm http://www.thermo.com/eThermo/CDA/Products/Product_Listing/0,1086,107687-161-161,00.html The first URL explains the theory of operation in general terms. The second URL is a manufacturer of conductivity cells. Best regards, Rich --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
As engineers, we should consider the safety implications of what we design, test or otherwise work on. EMI is part of that. What is considered a safety risk depends a great deal on corporate policy, the legal, political and popular climate in one's state of residence, and the kind of equipment under consideration. As it happens, the issue of pacemaker vulnerability is addressed in more regulations than USC 47. That is why, in the United States, we have not only a limit on microwave oven leakage, but also pacemaker warning signs on microwave ovens used by the public. The robotic arm is a great example. Others are automotive airbags, or electronically controlled brakes. These sort of things are the reason why industry associations develop limits of their own. Those limits accommodate both a performance requirement and practical aspects; they can't make the product too expensive to build or no one will be able to sell them at a profit. They can't be unreliable in the field or people won't buy them at all. And they can't cause too many problems, or the company will be sued. One factor weighs against another. We are at the balance point. Regards, Cortland Richmond (What I write here is mine alone. My employer does not Concur, agree or else endorse These words, their tone, or thought.) Andrew Carson wrote: I get the idea that we a missing the whole point of this discussion. Should we as Professional Safety Engineers and Product designers consider the safety implications of EMC emissions ? The answer is a definite Yes. We have a clear duty of care and responsibility to consider all implications of our products being used in there intended application. Even if the consideration on EMC emissions and safety is Do not be silly. We still have to at least consider it. ... --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
ADF approaches are still in use using non-directional beacons (NDB). I expect to get a lot of experience with them while pursuing my instrument rating this year. Of course, the other use for the ADF receiver is tuning in ball games while flying cross country as they cover the AM broadcast band, as well. Ghery Pettit -Original Message- From: Cortland Richmond [mailto:cortland.richm...@alcatel.com] Sent: Thursday, January 03, 2002 9:41 AM To: Ken Javor Cc: Mike Hopkins; cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I'm old enough, Ken, to remember ADF approaches! But laptop switchers often operate inband to frequencies used by aviation non-directional beacons. This makes them more of a threat than the harmonics from lower-frequency ones. It is also, of course, possible for the laptop's other emissions to interfere with an ILS or VOR receiver. Some of the complaints I've seen have not been rationally explicable, however. For example, at one of my former employer's (no longer in existence) a report was received that a laptop caused an aircraft to bank two degrees. I've worked with aircraft stabilization systems, and I've yet to figure out a mechanism how that could happen. Cortland (What I write here is mine alone. My employer does not Concur, agree or else endorse These words, their tone, or thought.) Ken Javor wrote: In my experience it is EXTREMELY unlikely that personal electronics could have disturbed ADF heading indication. The ADF sensor is an electrostatically shielded loop which is mounted typically on the belly of a transport class aircraft, well away from any passenger-conveyed intense sources of magnetic fields. The loop is very insensitive and requires quite a bit of magnetic field to respond and is completely insensitive to electric fields altogether. Further, no one would use ADF to line up an approach on a runway. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
While I take your point - I'll challenge with the equally valid argument that says show me the data that they do cause SIDS! What is worse never producing anything while checking an infinite set of possibilities or eventually discovering an unforeseen event? In the US it can take 7 to 10 years to research and approve all the issues around a new airport runway for example. The whole Konsai airport and the land it is sitting on in Japan took less time to construct than that. (Of course it is sinking - mind you.) There is some discussion that magnetic fields may be harmful (I'm not taking a side either way) so you might want to consider that around infants etc, but I don't think a study of gravity waves effects on cameras and infants is appropriate before releasing a product. The risk is there that at a latter date evidence may start to become available that suggests a link. That is the point when it becomes important to re-evaluate the hazards. Stretching the point a tad. I remember from an old product liability seminar a comment that said European Tort law had a provision that basically said if no-one (interesting little term) knew a hazard existed, the first use of asbestos comes to mind, then the manufacturer couldn't be held liable. The situation changes once it became known that it was a hazard and manufacturers continued to use it. Don't know if this still exists but it should. Others in this thread have suggested litigious creep into Europe from the US and I sadly suspect (again no proof) that it is likely. Many things we do very well - some of the things we do, we do less well. Gary -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: Wednesday, January 02, 2002 7:35 PM To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I read in !emc-pstc that Gary McInturff Gary.McInturff@worldwidepackets .com wrote (in 917063bab0ddb043af5faa73c7a835d40ac...@windlord.wwp.com ) about 'EMC-related safety issues', on Wed, 2 Jan 2002: Cameras don't cause disease likes SIDS. Please post your proof! That is the attitude of some (too many) safety experts these days. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I'm old enough, Ken, to remember ADF approaches! But laptop switchers often operate inband to frequencies used by aviation non-directional beacons. This makes them more of a threat than the harmonics from lower-frequency ones. It is also, of course, possible for the laptop's other emissions to interfere with an ILS or VOR receiver. Some of the complaints I've seen have not been rationally explicable, however. For example, at one of my former employer's (no longer in existence) a report was received that a laptop caused an aircraft to bank two degrees. I've worked with aircraft stabilization systems, and I've yet to figure out a mechanism how that could happen. Cortland (What I write here is mine alone. My employer does not Concur, agree or else endorse These words, their tone, or thought.) Ken Javor wrote: In my experience it is EXTREMELY unlikely that personal electronics could have disturbed ADF heading indication. The ADF sensor is an electrostatically shielded loop which is mounted typically on the belly of a transport class aircraft, well away from any passenger-conveyed intense sources of magnetic fields. The loop is very insensitive and requires quite a bit of magnetic field to respond and is completely insensitive to electric fields altogether. Further, no one would use ADF to line up an approach on a runway. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
Let's be real careful here and give credit where credit is due. The Pinto incident was in many ways not a safety issue with regard to safety testing and the safety engineers at Ford. The Ford Pinto fiasco was clearly a management issue. Tests were done to the 20 mph rear impact standard early in the Pinto development. Those tests clearly showed that the Pinto failed. Those tests were performed by Ford's safety team according to National Standards and were the results were reported to management. It was management who decided to go ahead with the failed design. The Pinto incident shows that we as safety engineers can really a take a horse to water but making it drink is a wholly different issue. - Doug McKean --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
I agree that this area is complex, and the ambiguity of the standards don't help. Special immunity requirements exist for the following types of alarm systems per the scope of EN 50130-4: intruder, hold-up, fire detection and fire alarm, social, CCTV for security applications, access control for security applications, and alarm transmission systems. OK, but what is meant by security applications? CENELEC Report R079-001:1996 defines CCTV surveillance system as: a CCTV surveillance system consists of camera equipment, monitoring and associated equipment for transmission and controlling purposes which may be necessary for the surveillance of a defined security zone. The report indicates that both EN 50130-4 and the ETSI EMC standards apply for RF CCTV products. EN50132-7 provides guidance on surveillance zone determination criteria. A CCTV surveillance installation is designed to monitor events of fundamental importance. These events might be hold up/theft, sabotage/vandalism, hazard, evaluation, etc. Typical examples of monitoring applications are: perimeter surveillance, access control, safety, property protection. Is that clear as mud? Let's go on to ETSI and see what we find. ETSI EN 301489-3 (EMC for Short Range Devices) specifies three classes of equipment for immunity purposes. The most severe limits are listed for, among other applications, domestic security, personal security and baby/nursery monitor - non-domestic. These devices are listed as Class 1 devices because the result of too low performance is physical risk to persons or goods. Class 2 devices (lower immunity), which include domestic transmission of sound and vision, may provide an inconvenience to persons, which cannot simply be overcome by other means. Class 3 devices (standard immunity) including a baby monitor may provide an inconvenience to persons which can simply be overcome by other means (e.g manual). Duh! So, take your best shot as to what the immunity requirements are for an RF CCTV camera for baby monitoring. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Gary McInturff [mailto:gary.mcintu...@worldwidepackets.com] Sent: Thursday, January 03, 2002 11:34 AM To: richwo...@tycoint.com; emc-p...@majordomo.ieee.org Subject: RE: EMC-related safety issues Richard, A monitoring system is a convenience it is not a guarantee of life saving functionality. It is a surveillance camera not a life support system. If and infant, in this case, needs special monitoring because of some know illness or just because you are really concerned parents, then move the child next to your room or in it rather than relying and then blaming a device with inherently less reliability than a human and especially and alert parent. The camera is a convenience, not a substitute for responsibility. The camera manufacturer isn't responsible other than building a product worth the cost of purchase, and that operates reasonably. They aren't responsible for building a device that is failsafe - at least not in this application. A failsafe surveillance system that is relied upon as the sole life protection system better have redundancy and the 5 nines of reliability and better. Like medical manufacturers they had better include in the purchase price the cost of just and unjust lawsuits. People expect medical equipment to do no harm and to not be the cause of death or injury. That's the business they are in, and they do quite handsomely at it for the most part. They have to do it because they are in that kind of business - life support or protection, and are not just casual observers. People justifiably want and expect them to have a product that works. None of this sounds like a standard off the shelf camera system to me. A simpler example that happen around here some years ago was a youngster that was playing hockey with an approved hockey helmet. Long story short, he was hit in the head with a puck and the helmet failed to perform its basic function and the young man died. The parents were, in my opinion, absolutely justified in suing the equipment manufacturer. because the product was being used in its intended fashion. Unless the camera manufacturer is making claims of life saving protection rather than simple convenience monitoring they aren't culpable. Obviously, my own opinions Gary -Original Message- From: richwo...@tycoint.com [mailto:richwo...@tycoint.com] Sent: Thursday, January 03, 2002 5:26 AM To: emc-p...@majordomo.ieee.org Subject: RE: EMC-related safety issues Ken, let me address the specific case you mentioned - the RF camera used for baby surveillance. In that particular application, surveillance for the protection of persons, more severe immunity requirements apply. Those requirements are either specified in EN 50130-4 or the particular ETSI product EMC standard. A manucturer should understand that the product may be used for protection of persons
Re: EMC-related safety issues
I agree with what you say, but at least in this country the anti-business pendulum has swung farther than you imagine. A couple examples. Thurman Munson, a Yankee catcher in the '70s, was killed in his twin engine Cessna jet. He crashed short of a runway. His estate sued Cessna, not on the grounds that the jet was defective, but that Cessna had sold Munson more aircraft than he was capable of handling. Cessna demonstrated that it had sold Munson the model he wanted, but the plaintiff claimed that it was Cessna' duty to assess Munson's skills as a pilot and tell him, the customer, what aircraft they would sell him. I don't recall how the verdict was rendered, but I know Cessna paid something. Another case involved the death of a child in an automobile accident involving a minivan. The child was thrown from the vehicle, in part because the rear door sprang open on impact. Plaintiff claimed the door was poorly designed and that the child would have remained in the vehicle and maybe not been killed had the doors remained closed. Defendant pointed out that child was not restrained in vehicle, he was up and and about at the moment of impact. Documentation supplied with vehicle clearly states all passengers should wear restraining belts. Plaintiff countered that defendant should have known that if they built a vehicle as large as a minivan that kids would be up and about and vehicle should have been designed with that in mind. Again do not recall verdict but I am sure plaintiff did not walk away empty-handed. Agreed that a manufacturer is responsible for the safety of a product put into normal use. That was established by case law as far back as the Babylonian Code of Hammurabi, wherein an architect who builds a house that collapses and kills the owner is liable to the same fate. But the manufacturer today labors under a presumption of evil: if he makes a profit from selling a product, he must have skimped somewhere, because profits are intrinsically evil. -- From: James, Chris c...@dolby.co.uk To: 'acar...@uk.xyratex.com' acar...@uk.xyratex.com, emc-p...@majordomo.ieee.org Subject: RE: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Thu, Jan 3, 2002, 8:25 AM Ken, I don't think anyone could disagree with your sentiments. The problem is attributing the level of liability between user and manufacturer. Car manufacturers sleep at night yet their products kill thousands each year, they design them to high standards yet by their use they still kill and maim. Do we hold them liable, no, in 99.9% of cases we don't. You slip down the stairs and break your leg, do you sue: the caveman who invented the staircase? your shoe manufacturer for using a shoe sole incompatible with the stair carpet? the stair carpet manufacturer for using material incompatible with the shoe sole material? the distiller for not putting a warning on the bottle of whisky you just drank It's reasonable responsibility/diligence that needs defining, not spurious emissions!! In addition the legal fraternity should have some standards imposed upon them to put an end to pure gold digging through litigation that seems to just escalate and to which we thus have to pander. If every foreseeable mis-use of every commodity sold was accounted for then no-one would sell anything. Chris __ Chris James Engineering Services Manager Dolby Laboratories, Inc. (UK) -Original Message- From: acar...@uk.xyratex.com [mailto:acar...@uk.xyratex.com] Sent: 03 January 2002 12:54 To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I get the idea that we a missing the whole point of this discussion. Should we as Professional Safety Engineers and Product designers consider the safety implications of EMC emissions ? The answer is a definite Yes. We have a clear duty of care and responsibility to consider all implications of our products being used in there intended application. Even if the consideration on EMC emissions and safety is Do not be silly. We still have to at least consider it. It has been stated that CISPR22 and CFR Title 47 Part 15b is only concerned with interfering with radio transmissions. This is true and why the enforcement falls under the Federal Communications Commission. But not all products fall under this remit and could quite happily be emitting large EM fields and comply with all current US legislation. Take for example the line surge equipment you use to test immunity to EN61000-4-5, exempt from the Part 15B under section 15.29 as A digital device used exclusively as industrial, commercial, or medical test equipment. And clearly not medical equipment. Yet when operated can produce a magnetic field that will interfere with the operation of old style pacemakers. Should you consider this when addressing the safe design of the product, or blindly state you meet all applicable EMC regulations for this product. With my unit the
Re: milstandards website?
Try http://astimage.daps.dla.mil/quicksearch/ Jacob Z. Schanker, P.E. 65 Crandon Way Rochester, NY 14618 Phone: 585 442 3909 Fax: 585 442 2182 j.schan...@ieee.org - Original Message - From: Brodie Pedersen brod...@nonin.com To: emc-p...@majordomo.ieee.org Sent: Thursday, January 03, 2002 9:32 AM Subject: milstandards website? | | Could some one post the URL for the mil stds web site please, I seem to | have lost it. | Thank you in advance. | | Brodie Pedersen | Nonin Medical Inc. | Plymouth MN USA | | --- | This message is from the IEEE EMC Society Product Safety | Technical Committee emc-pstc discussion list. | | Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ | | To cancel your subscription, send mail to: | majord...@ieee.org | with the single line: | unsubscribe emc-pstc | | For help, send mail to the list administrators: | Michael Garretson:pstc_ad...@garretson.org | Dave Healddavehe...@mediaone.net | | For policy questions, send mail to: | Richard Nute: ri...@ieee.org | Jim Bacher: j.bac...@ieee.org | | All emc-pstc postings are archived and searchable on the web at: | No longer online until our new server is brought online and the old messages are imported into the new server. | --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
Richard, A monitoring system is a convenience it is not a guarantee of life saving functionality. It is a surveillance camera not a life support system. If and infant, in this case, needs special monitoring because of some know illness or just because you are really concerned parents, then move the child next to your room or in it rather than relying and then blaming a device with inherently less reliability than a human and especially and alert parent. The camera is a convenience, not a substitute for responsibility. The camera manufacturer isn't responsible other than building a product worth the cost of purchase, and that operates reasonably. They aren't responsible for building a device that is failsafe - at least not in this application. A failsafe surveillance system that is relied upon as the sole life protection system better have redundancy and the 5 nines of reliability and better. Like medical manufacturers they had better include in the purchase price the cost of just and unjust lawsuits. People expect medical equipment to do no harm and to not be the cause of death or injury. That's the business they are in, and they do quite handsomely at it for the most part. They have to do it because they are in that kind of business - life support or protection, and are not just casual observers. People justifiably want and expect them to have a product that works. None of this sounds like a standard off the shelf camera system to me. A simpler example that happen around here some years ago was a youngster that was playing hockey with an approved hockey helmet. Long story short, he was hit in the head with a puck and the helmet failed to perform its basic function and the young man died. The parents were, in my opinion, absolutely justified in suing the equipment manufacturer. because the product was being used in its intended fashion. Unless the camera manufacturer is making claims of life saving protection rather than simple convenience monitoring they aren't culpable. Obviously, my own opinions Gary -Original Message- From: richwo...@tycoint.com [mailto:richwo...@tycoint.com] Sent: Thursday, January 03, 2002 5:26 AM To: emc-p...@majordomo.ieee.org Subject: RE: EMC-related safety issues Ken, let me address the specific case you mentioned - the RF camera used for baby surveillance. In that particular application, surveillance for the protection of persons, more severe immunity requirements apply. Those requirements are either specified in EN 50130-4 or the particular ETSI product EMC standard. A manucturer should understand that the product may be used for protection of persons and apply the appropriate immunity requirements. Failure to do so, could create a liability issue. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, January 02, 2002 2:22 PM To: cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I have read a part of the IEE guide mentioned below. What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or misuse of the equipment he sells in concert with every other type of equipment made or that might be made at some time in the future. This document is a trial lawyer's dream. It takes us from a society in which a sale was deemed a transaction of mutual benefit between equals to a society in which an Omniscient Producer must cater to the needs of an ignorant, childlike Consumer, and in direct corollary, any misuse of any product by any consumer is deemed proof that the Omniscient Producer was profiting by taking advantage of a helpless victim. I realize this document merely reflects this prevalent view, but the idea that an Industry group would provide such a smoking gun for some trial lawyer to use in defense of some poor misled swindled consumer is, to say the least, troubling. To say that Industry standards don't go far enough, that it is the responsibility of the Producer to be able to determine all possible environments and failure modes that might ever occur is placing an impossible burden and any rationale entity, upon reading this document will immediately cease production of anything that could conceivably ever malfunction in anyway whatsoever. Case in point: A friend of mine bought one of these 2.4 GHz remote miniature video cameras with integral IREDs and is able to monitor his infant twins from his own bedroom, even in the middle of the night with no lights on in the twins' bedroom. Suppose that 2.4 GHz link is disturbed in some way and he misses something important happening in that bedroom. Is the manufacturer of that video system responsible for any ill that then befalls my friend's twins? I think
Re: power supply to GOST 30429-96
Hi Lou: Try checking the AC input wiring to the power supply, and verify that it doesn't have loops across the power supply. Magnetic fields from the transformer may be high, and excessive wire length acts as a magnetic pickup. 1) Are the parameters you posted for the conducted emission limits accurate? I tried plotting them, and got a big discontinuity at 0.15MHz. 2) Is there any change in the conducted emission test setup below 0.15MHz? 3) Does the GOST radiated emission standard specify an E-field (dipole, biconical, log periodic, etc.) antenna below 30MHz? Below 0.15MHz? Or are there magnetic loop antennas for some of the test ranges? I have a hard time imagining E-field measurements below 30MHz at a 3m distance. Patrick Lawler plaw...@west.net On Fri, 21 Dec 2001 10:19:22 -0800, you wrote: snip The requirements for EMC of radio equipment in Russia (as well as in several other CIS countries) are set by the standard GOST 30429-96 (Electromagnetic Compatibility of technical equipment. Man-made noise from equipment and apparatus used t6ogether with service receiver systems of civil application. Limits and test methods), according to this standard the following measurement must be done. 1. Conducted Emissions Frequency range Limits, dB(uV) 0.009 MHz - 0.15 MHz U = 90 - 28.9lg(f/0,01) (Quasi-peak) 0.15 MHz - 0.5 MHz U = 66 - 22.7lg(f/0,15) (Quasi-peak) 0.5 MHz - 6 MHz U = 54 - 12.97lg(f/0,5) (Quasi-peak) 6 MHz - 30 MHzU = 40 (Quasi-peak) 30 MHz - 100 MHzU = 48 (Quasi-peak) 40 (Average) This test is done looking at the emissions from the 220 V power cables, using a LISN 2. Radiated Emissions Frequency range Limits, dB(uV/m) 0.01 MHz - 0.15 MHzE = 60 - 20.4lg(f/0.01) 0.15 MHz - 30 MHz E = 37 - 7.39lg(f/0.15) 30 MHz - 100 MHzE = 36 - 21.0lg(f/0.30) 100 MHz - 1000 MHzE = 25 + 20.0lg(f/100) According to GOST 30429-96 this test is done at 3 meters in frequency range 0.01MHz - 30 MHz and at 1 meter in frequency range 30 MHz - 1000 MHz in the screen room. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: milstandards website?
Brodie, For Mil Stds go to http://astimage.daps.dla.mil/quicksearch/ Some standards are not available in PDF format to download but are available in hard copy and are still free. You just have to set up a customer number and order the desired standard via fax or e-mail. This is a great resource! Bill Fleury -Original Message- From: Brodie Pedersen [mailto:brod...@nonin.com] Sent: Thursday, January 03, 2002 8:33 AM To: emc-p...@majordomo.ieee.org Subject: milstandards website? Could some one post the URL for the mil stds web site please, I seem to have lost it. Thank you in advance. Brodie Pedersen Nonin Medical Inc. Plymouth MN USA --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EN60529
I read in !emc-pstc that Crabb, John jo...@exchange.scotland.ncr.com wrote (in B6CD5947CF30D411A1350050DA4B75FF03C23387@sgbdun200.scotland.n cr.com) about 'EN60529', on Thu, 3 Jan 2002: John, I have forwarded this information to the chairman of BSI committee EPL/74 (which deals with EN60950), with the suggestion that CENELEC be asked to get EN60529 removed from the list of LVD notified standards. We'll see what happens. Good. I will do the same in EPL/92. A double-whammy, indeed. On the same subject, TC74 is working on requirements for outdoor IT equipment, (in which I am involved). I believe that while IEC 60529 may well be used to prove that a sealed box is watertight, a prolonged rain test, such as the UL one hour rain test, is more relevant to real IT equipment (such as my ATMs) which interact with the public, and which will have openings which have to be designed to eliminate ingress of water, or which have water management systems to divert water away from areas where a hazard could otherwise be introduced. EN60529 is very old; you should propose a full revision of the IEC standard, to align more closely with the UL! -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
I understand in this particular case the RF camera may have been marketed for baby surveillance. The majority of camera systems, wired and wireless, that I have seen are not marketed in this manner. Most are advertised as security/surveillance cameras. Are you implying that all manufacturers of these camera systems must consider the possible use of the products for the protection of persons? What if the manufacturer clearly states in the user instructions that the product is not suitable for the protection of persons? I have always understood that a manufacturer can meet obligations by addressing intended use only. For example if I was to manufacture a kettle, I would state for boiling water only in the relevant documentation. Some of the recent messages in this thread would seem to imply that I would have to consider the possible use of the kettle being used to boil something other than water, gasoline for example. Am I then liable from the damages resulting from the possible ignition of the volatile fumes from some undefined energy source, i.e. lack of emc immunity? Enci At 08:26 03/01/02 -0500, Richard Woods wrote: Ken, let me address the specific case you mentioned - the RF camera used for baby surveillance. In that particular application, surveillance for the protection of persons, more severe immunity requirements apply. Those requirements are either specified in EN 50130-4 or the particular ETSI product EMC standard. A manucturer should understand that the product may be used for protection of persons and apply the appropriate immunity requirements. Failure to do so, could create a liability issue. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Ken Javor[mailto:ken.ja...@emccompliance.com] Sent: Wednesday, January 02,2002 2:22 PM To: cherryclo...@aol.com;emc-p...@majordomo.ieee.org Subject: Re: EMC-related safetyissues To say that Industrystandards don't go far enough, that it is the responsibility of the Producerto be able to determine all possible environments and failure modes that mightever occur is placing an impossible burden and any rationale entity, uponreading this document will immediately cease production of anything that couldconceivably ever malfunction in anyway whatsoever. But this safety guide saysyes, and places the manufacturer at risk. -- From:cherryclo...@aol.com To: emc-p...@majordomo.ieee.org Subject: Re:EMC-related safety issues Date: Wed, Jan 2, 2002, 9:49 AM Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it. Of course I am passionate about the IEE guide - my colleagues and I spent a long time working on it! When I discovered you were criticising it to the emc-pstc of course I had to respond - but I was not (and am not) trying to defend the guide, merely trying to find out just exactly what it is that you (and your silent 'equally senior experts') don't like about it so I can get it improved. I am sorry if my wordy emails give the wrong impression - the simple fact is that I always write too much (as any editor who has had an article from me will confirm!). Once again I ask you - and everyone else in the entire EMC or Safety community world-wide - to read the IEE's guide and let me have constructive comments about how to improve it. You can easily download it for free from www.iee.org.uk/Policy/Areas/Electro (- you only need to download the 'core' document for this exercise and can leave the nine 'industry annexes' for later criticism). I'll make it easy for anyone to comment even if they haven't read the Core of the IEE's guide ...the guide is based on the following engineering approach, explicitly stated at the start of its Section 4 and duplicated below. * To control EMC correctly for functional safety reasons, hazard and risk assessments must take EM environment, emissions, and immunity into account. The following should be addressed: 1) The EM disturbances, however infrequent, to which the apparatus might be exposed 2) The foreseeable effects of such disturbances on the apparatus 3) How EM disturbances emitted by the apparatus might affect other apparatus (existing or planned)? 4) The foreseeable safety implications of the above mentioned disturbances (what is the severity of the hazard, the scale of the risk, and the appropriate safety integrity level?) 5) The level of confidence required to verify that the above have been fully considered and all necessary actions taken to achieve the desired level of safety * Please - anybody and everybody out
Re: EMC-related safety issues
I read in !emc-pstc that cherryclo...@aol.com wrote (in e5.11a0fabe.296 5d...@aol.com) about 'EMC-related safety issues', on Thu, 3 Jan 2002: Over the course of this correspondence (and in earlier postings to emc-pstc) you have cast doubt on the IEE's guide to EMC and Functional Safety without being in any way specific. No, Keith, as far as I know I have not done that. All my remarks were, or were intended to be, in reference to IEC work. But I agree that the matter has moved on. At least I hope that we can now agree that EMC and safety IS a controversial issue! -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6ABC4FD5@flbocexu05) about 'EMC-related safety issues', on Thu, 3 Jan 2002: Ken, let me address the specific case you mentioned - the RF camera used for baby surveillance. In that particular application, surveillance for the protection of persons, more severe immunity requirements apply. Those requirements are either specified in EN 50130-4 or the particular ETSI product EMC standard. A manucturer should understand that the product may be used for protection of persons and apply the appropriate immunity requirements. Failure to do so, could create a liability issue. But that standard is INTENDED to apply to security and crowd-control cameras in stores, places of public assembly and sheltered accommodation. To 'read it on' to a simple camera used as a sophisticated baby alarm (on the grounds that it is a 'social alarm' application) is just the sort of man-trap that has many of us very concerned indeed. I'm going to get one of those cameras and mount it in my car. Now it has to meet automotive immunity requirements. Has the manufacturer thought of that? If the car camera works, I'll put two more in my boat and plane. No doubt that has been taken into account as well.(;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
EMC-related safety issues
The key word in EMC is compatibility. This implies that electrical and electronic equipment are (ideally) designed so that each can operate normally in the presence of another. This requires limiting both the emissions and sensitivity of such devices. Historically, only a limited number of product types have been subject to EMC limits. Most EMC requirements are based on the assumption that the emission of specific frequencies is more likely to interfere with other equipment than white or broad spectrum emissions. For example, the FCC rules apply to devices using clocked frequencies of 10K and above, but place no limits on vacuum cleaners, blenders, arc welders, etc. unless they contain clocked electronics. The exclusion of so many products from emission/susceptibility requirements is often the cause of EMC related accidents. Some years ago, in one of the U.S. Southwestern states, the local public safety (police/fire/etc) communications were often disrupted by an unknown source. The source was eventually traced to a pin ball machine in a roadside tavern. The owner was told he must get rid of the machine. A few weeks later, the noise re-appeared. It turned out that the same pinball machine was placed in service at another pub in the county. In some cases, the interaction of two devices is not exactly foreseeable. We once received reports of one of our typewriters typing occasionally without human assistance. It turned out that the typewriter was in use fairly close to an airport radar beacon. When the radar beam swept the area of the typewriter installation, it could cause the capacitor coupled keyboard to create false keystrokes. We added a large grounded template to cover most of the interior keypad area, to increase its immunity. There can be, and have been, safety related consequences of EM incompatibility. In the 1980's (as I recall) a U.S. aircraft carrier suffered a major EMC disaster. The powerful on-board electronics, particularly the radar units, triggered the launch of a missle from one of the on-deck planes. The missle struck the bridge tower, resulting in a fire costing millions of dollars in repairs and the loss of some lives. I cannot find my copy of this event, reported some years ago in one of the electronics magazines. In general, Navies are far more sensitive to EMI due to the concentration of on- board electronics. As a result, the U.S. Navy version of the Blackhawk helicopter had few EMI problems, while the Army version had several early crashes due to interference from nearby radio stations. The moral, if there is one, is that emissions and susceptibility of unregulated devices is more often the problem than the emissions or susceptibility of a regulated device. George Alspaugh Lexmark International --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
That is exactly the point. These things started out as intended for inventory shrinkage control in retail outlets but because someone might use them for something else, the manufacturer is liable for their malfunction, even though the device makes the consumer's life easier. The new device is not considered a tool but a crutch from the get-go. This is an anti-business environment that even the old behind the Iron Curtain Communists could not have imagined. -- From: richwo...@tycoint.com To: emc-p...@majordomo.ieee.org Subject: RE: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Thu, Jan 3, 2002, 7:26 AM Ken, let me address the specific case you mentioned - the RF camera used for baby surveillance. In that particular application, surveillance for the protection of persons, more severe immunity requirements apply. Those requirements are either specified in EN 50130-4 or the particular ETSI product EMC standard. A manucturer should understand that the product may be used for protection of persons and apply the appropriate immunity requirements. Failure to do so, could create a liability issue. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, January 02, 2002 2:22 PM To: cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I have read a part of the IEE guide mentioned below. What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or misuse of the equipment he sells in concert with every other type of equipment made or that might be made at some time in the future. This document is a trial lawyer's dream. It takes us from a society in which a sale was deemed a transaction of mutual benefit between equals to a society in which an Omniscient Producer must cater to the needs of an ignorant, childlike Consumer, and in direct corollary, any misuse of any product by any consumer is deemed proof that the Omniscient Producer was profiting by taking advantage of a helpless victim. I realize this document merely reflects this prevalent view, but the idea that an Industry group would provide such a smoking gun for some trial lawyer to use in defense of some poor misled swindled consumer is, to say the least, troubling. To say that Industry standards don't go far enough, that it is the responsibility of the Producer to be able to determine all possible environments and failure modes that might ever occur is placing an impossible burden and any rationale entity, upon reading this document will immediately cease production of anything that could conceivably ever malfunction in anyway whatsoever. Case in point: A friend of mine bought one of these 2.4 GHz remote miniature video cameras with integral IREDs and is able to monitor his infant twins from his own bedroom, even in the middle of the night with no lights on in the twins' bedroom. Suppose that 2.4 GHz link is disturbed in some way and he misses something important happening in that bedroom. Is the manufacturer of that video system responsible for any ill that then befalls my friend's twins? I think not. But this safety guide says yes, and places the manufacturer at risk. -- From: cherryclo...@aol.com To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Wed, Jan 2, 2002, 9:49 AM Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it. Of course I am passionate about the IEE guide - my colleagues and I spent a long time working on it! When I discovered you were criticising it to the emc-pstc of course I had to respond - but I was not (and am not) trying to defend the guide, merely trying to find out just exactly what it is that you (and your silent 'equally senior experts') don't like about it so I can get it improved. I am sorry if my wordy emails give the wrong impression - the simple fact is that I always write too much (as any editor who has had an article from me will confirm!). Once again I ask you - and everyone else in the entire EMC or Safety community world-wide - to read the IEE's guide and let me have constructive comments about how to improve it. You can easily download it for free from www.iee.org.uk/Policy/Areas/Electro (- you only need to download the 'core' document for this exercise and can leave the nine 'industry annexes' for later criticism). I'll make it easy for anyone to comment even if they haven't read the Core of the IEE's guide ...the guide is based on the following engineering approach, explicitly stated at the start of its Section 4 and duplicated below. * To
Re: EMC-related safety issues
---BeginMessage--- Dear John Maybe I should have been more explicit. Over the course of this correspondence (and in earlier postings to emc-pstc) you have cast doubt on the IEE's guide to EMC and Functional Safety without being in any way specific. Now you are saying that you haven't read it and don't wish to comment on it, but you haven't retracting (or given any substantive reasons for) any of your earlier negative comments. OK, I'm not really happy with the result but if you like we can call it quits and stop wasting emc-pstc members' time. Regards, Keith Armstrong In a message dated 02/01/02 21:19:53 GMT Standard Time, j...@jmwa.demon.co.uk writes: Subj:Re: EMC-related safety issues Date:02/01/02 21:19:53 GMT Standard Time From:j...@jmwa.demon.co.uk (John Woodgate) Sender:owner-emc-p...@majordomo.ieee.org Reply-to: A HREF=mailto:j...@jmwa.demon.co.uk;j...@jmwa.demon.co.uk/A (John Woodgate) To:emc-p...@majordomo.ieee.org I read in !emc-pstc that cherryclo...@aol.com wrote (in 63.44c9e61.29648...@aol.com) about 'EMC-related safety issues', on Wed, 2 Jan 2002: Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it. I quite specifically said that I refrained from comment on it and I did not comment on it. Furthermore, I don't intend to. Make that into a 'negative impression', if you can reasonably do so. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk ---End Message---
Re: EMC-related safety issues
---BeginMessage--- All I know about the issue of the laptop interfering with the compass is from the IEE's Guide to EMC and Functional Safety, copied below: * A routine flight over Dallas-Fort Worth was disrupted when one of the compasses suddenly shifted 10 degrees to the right. The pilot asked if any passenger was operating an electronic device, and finding that a laptop computer had just been turned on requested that it be turned off, whereupon the compass returned to normal. Following RTCA guidelines the pilot requested that the laptop be turned on again 10 minutes later, when the compass error returned. Ref: Compliance Engineering (European edition) Nov/Dec 1996 p12 * I am led to believe that the incident was one that was officially investigated, and not just someone's bad dream. Unfortunately CE Magazine's on-line archives only go back to 1999, so I can't quickly find out more about this incident. But I am sure there is more to a compass in a modern airplane than simply a bar magnet with a pointer attached. For example I have designed compass systems for ships that used servomotors. So I assumed that the emissions from the laptop were demodulated in some compass circuitry, probably after being picked up by a cable from a remote compass sensor, causing the error (see Edmund A Woodcox's earlier message 02/01/02 19:58:08 GMT). A quick trawl through the 'Banana Skins' columns in the EMC + Compliance Journal's archives (at www.compliance-club.com) reveals that most anecdotal or official reports of interference problems are either caused by radio transmitters (including ISM equipment used for the RF processing of materials in industry or medicine) or are suffered by radio receivers. However, there are some reports which don't fit into the above two categories, where a device that one might expect to comply with EMC emissions standards has caused interference with a device that is not a radio receiver. These reports can be found in the above archives as follows: No. 2, 4 Feb 98 No. 35 Dec 98 No. 49 Jun 99 No. 66 Dec 99 No. 96 Aug 00 No. 120 Apr 01 No. 129, 137 Jun 01 No. 157 Oct 01 But don't forget that publication in a magazine is not proof that the incident occurred! Regards, Keith Armstrong In a message dated 02/01/02 16:48:43 GMT Standard Time, ken.ja...@emccompliance.com writes: Subj:Re: EMC-related safety issues Date:02/01/02 16:48:43 GMT Standard Time From:ken.ja...@emccompliance.com (Ken Javor) To:cherryclo...@aol.com I forgot to mention the issue of the compass in my earlier reply. First a statement of fact. A compass is a magnet, and it can only respond to a dc or very slowly varying ac magnetic field. It is physically impossible for the compass movement itself to respond to rf. There is the concept of the compass safe distance and a requirement to measure it is included in RTCA/DO-160, Environmental Conditions for Aircraft. But the effect is limited to a dc offset due to magnetic material. I cannot see a laptop causing such a problem unless it were in the immediate vicinity of the compass, which is unlikely in an aircraft. To illustrate how utterly insensitive a compass is to rf, consider the following true story. A flux-gate (a type of compass used on aircraft) was reported to be sensitive to rf energy when the HF transmitter on a particular aircraft was keyed. The frequency didn't matter, when the transmitter was keyed, the heading indication shifted. The flux-gate was located in the immediate vicinity of the HF antenna, which was the leading edge of the vertical stabilizer. It turned out that the 200 Watt rf transmission had nothing to do with the interference. When an HF transmission is keyed, an antenna tuner adjusts a tuning coil to match the antenna to the rf power source and that required 28 Vdc current to flow and it was that relatively low-level current, not the 200 Watts of radiated rf power that caused the offset. I wonder if the laptop disturbing a compass story is a distortion of the DC-10 event I related in the response to Mr. Woodgate's postings? ---End Message---
RE: EMC for cardio : wich standard apply?
Paolo, The Medical Devices Directive enforces you to use the standards listed in the Official Journal as follows: Safety: EN60601-2-25 + A1 EMC : EN 60 601-1-2 Any questions, please e-mail or call. This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 -Original Message- From: Paolo Peruzzi [mailto:paolo.peru...@esaote.com] Sent: Thursday, January 03, 2002 3:15 PM To: emc-p...@majordomo.ieee.org Subject: EMC for cardio : wich standard apply? hello, I have to test an electrocardiograph for EMC , but I'm in trouble with the standard to apply. There is IEC 60601-2-25 -A1, Particular requirements for the safety of elecrocardiographs, that deals with EMC, and refers to IEC 60601-1-2 1st ed.(1993, now superseded) and is still valid, as far as I know. But now we have the new edition of IEC 60601-1-2, and its requirements are very different from 60601-2-25-A1 ones. The old edition is replaced by the new one, but what about those particular standards based on it? So I don't know which standard I have to apply. Can anybody out of there dispel my doubts? Best regards p.p. - ESAOTE S.p.A. Paolo Peruzzi Research Product DevelopmentDesign Quality Control Via di Caciolle,15tel:+39.055.4229306 I- 50127 Florence fax:+39.055.4223305 e-mail: paolo.peru...@esaote.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: milstandards website?
Brodie, It is http://astimage.daps.dla.mil/online/new/ You do not need an account even though at the top of the page is a place to enter your account number and password. If you just click on Quick Search you can find everything you need. Kurt Andrews Compliance Engineer Tracewell Systems, Inc. 567 Enterprise Drive Westerville, Ohio 43081 voice: 614.846.6175 toll free: 800.848.4525 fax: 614.846.7791 http://www.tracewellsystems.com/ -Original Message- From: Brodie Pedersen [mailto:brod...@nonin.com] Sent: Thursday, January 03, 2002 9:33 AM To: emc-p...@majordomo.ieee.org Subject:milstandards website? Could some one post the URL for the mil stds web site please, I seem to have lost it. Thank you in advance. Brodie Pedersen Nonin Medical Inc. Plymouth MN USA --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EN60529
John, I have forwarded this information to the chairman of BSI committee EPL/74 (which deals with EN60950), with the suggestion that CENELEC be asked to get EN60529 removed from the list of LVD notified standards. We'll see what happens. On the same subject, TC74 is working on requirements for outdoor IT equipment, (in which I am involved). I believe that while IEC 60529 may well be used to prove that a sealed box is watertight, a prolonged rain test, such as the UL one hour rain test, is more relevant to real IT equipment (such as my ATMs) which interact with the public, and which will have openings which have to be designed to eliminate ingress of water, or which have water management systems to divert water away from areas where a hazard could otherwise be introduced. Regards, John Crabb, Development Excellence (Product Safety) , NCR Financial Solutions Group Ltd., Kingsway West, Dundee, Scotland. DD2 3XX E-Mail :john.cr...@scotland.ncr.com Tel: +44 (0)1382-592289 (direct ). Fax +44 (0)1382-622243. VoicePlus 6-341-2289. -Original Message- From: John Woodgate [mailto:j...@jmwa.demon.co.uk] Sent: 02 January 2002 21:30 To: emc-p...@majordomo.ieee.org Subject: Re: EN60529 I read in !emc-pstc that richwo...@tycoint.com wrote (in 846BF526A205F8 4BA2B6045BBF7E9A6ABC4FD0@flbocexu05) about 'EN60529', on Wed, 2 Jan 2002: It is referenced in the OJ under the LVD, yet a reading of the standard indicates that it is a basic standard intended to be referenced in product standards. It appears to be a mistake, because, as you say, it is a Basic Standard. Astonishing as it must seem to mere mortals, the CENELEC Technical Board is not utterly infallible. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: milstandards website?
Brodie, Here is my collection of URLs--I'm not sure which ones are still valid, however. Regards, Dan http://www.dodssp.daps.mil/ http://agena.spawar.navy.mil/ http://www-chas.nosc.mil/spawar/pdf/MIL461D.PDF http://www-chas.nosc.mil/spawar/pdf/MIL462.PDF http://www-chas.nosc.mil/spawar/pdf/MIL464.PDF (MIL-STD-461E = MIL-STD-461D + MIL-STD-462D): http://assist.daps.mil/eAccess/index.cfm?ident_number=35789 register at: http://astimage.daps.dla.mil/online/ or: http://www.dodssp.daps.mil http://astimage.daps.dla.mil/quicksearch (latest) X-MimeOLE: Produced By Microsoft Exchange V6.0.4712.0 content-class: urn:content-classes:message MIME-Version: 1.0 Subject: milstandards website? Date: Thu, 3 Jan 2002 08:32:46 -0600 X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: milstandards website? Thread-Index: AcGUY1PFjZgoBUNiSjKtSvxmSEWFHw== From: Brodie Pedersen brod...@nonin.com To: emc-p...@majordomo.ieee.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by ruebert.ieee.org id g03EXYJ24706 X-Resent-To: Multiple Recipients emc-p...@majordomo.ieee.org X-Listname: emc-pstc X-Info: Help requests to emc-pstc-requ...@majordomo.ieee.org X-Info: [Un]Subscribe requests to majord...@majordomo.ieee.org X-Moderator-Address: emc-pstc-appro...@majordomo.ieee.org Could some one post the URL for the mil stds web site please, I seem to have lost it. Thank you in advance. Brodie Pedersen Nonin Medical Inc. Plymouth MN USA --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
Dear Ken I understand your concern and your comments, but all the IEE's guide was trying to do was make people aware of the legal situation as it actually exists - and recommend what engineers need to do to reduce their employers' liability risks under present-day legislation. (Bearing in mind that some safety modern laws in the EU can allow design engineers to be held personally responsible as well as their employers.) It appears to be a fact that exactly the situation you describe (and complain about) below already exists due to the present-day Product Liability Laws in the EU (and, I think, in the USA too). So please don't shoot the messenger! The only real defence under these Product Liability laws, is, as I understand (I am no lawyer) is that 'the product met the world-wide state of the art in safety design at the time it was placed on the market for a consumer'. This is of course a difficult task, but one which automobile manufacturers and many other large companies are well aware of and already have the procedures to deal with, since they are prime targets for 'no win - no fee' liability lawyers. In the EU the General Product Safety Directive is going much further than the above by making it mandatory for a manufacturer to consider advances in the state of the art in safety design after a product has been placed on the market. They are required to contact customers if any significant safety improvements can be made even many years after they purchased the product - possibly even recalling a product and modifying or replacing it. It seems that consumer groups are getting stronger and having more of an impact on the legislative process in the EU, and maybe elsewhere in the world too. Some manufacturers don't like the present direction of product liability legislation, whereas others see it as a commercial opportunity. As manufacturers we may complain about these developments, but as consumers we might take a different view! Many people in the EMC world are not used to the way things are done in the world of safety and product liability. The IEE's guide is intended to help fill that gap in their knowledge. Regards, Keith Armstrong In a message dated 02/01/02 19:22:44 GMT Standard Time, ken.ja...@emccompliance.com writes: Subj:Re: EMC-related safety issues Date:02/01/02 19:22:44 GMT Standard Time From:ken.ja...@emccompliance.com (Ken Javor) To:cherryclo...@aol.com, emc-p...@majordomo.ieee.org I have read a part of the IEE guide mentioned below. What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or misuse of the equipment he sells in concert with every other type of equipment made or that might be made at some time in the future. This document is a trial lawyer's dream. It takes us from a society in which a sale was deemed a transaction of mutual benefit between equals to a society in which an Omniscient Producer must cater to the needs of an ignorant, childlike Consumer, and in direct corollary, any misuse of any product by any consumer is deemed proof that the Omniscient Producer was profiting by taking advantage of a helpless victim. I realize this document merely reflects this prevalent view, but the idea that an Industry group would provide such a smoking gun for some trial lawyer to use in defense of some poor misled swindled consumer is, to say the least, troubling. To say that Industry standards don't go far enough, that it is the responsibility of the Producer to be able to determine all possible environments and failure modes that might ever occur is placing an impossible burden and any rationale entity, upon reading this document will immediately cease production of anything that could conceivably ever malfunction in anyway whatsoever. Case in point: A friend of mine bought one of these 2.4 GHz remote miniature video cameras with integral IREDs and is able to monitor his infant twins from his own bedroom, even in the middle of the night with no lights on in the twins' bedroom. Suppose that 2.4 GHz link is disturbed in some way and he misses something important happening in that bedroom. Is the manufacturer of that video system responsible for any ill that then befalls my friend's twins? I think not. But this safety guide says yes, and places the manufacturer at risk. -- From: cherryclo...@aol.com To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Wed, Jan 2, 2002, 9:49 AM Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it. Of course I am passionate about the IEE guide - my colleagues and I spent a long
milstandards website?
Could some one post the URL for the mil stds web site please, I seem to have lost it. Thank you in advance. Brodie Pedersen Nonin Medical Inc. Plymouth MN USA --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
The general impression in Europe is that the 'culture of blame' began in the USA, leading to such warning messages as Do not use this appliance to dry pet animals on microwave ovens. It often seems that legal trends begin in the States and take about 10 years to get over to Europe. It seems a pity that the liability laws have got themselves into this state, but it was not my doing anyway and maybe some manufacturers did need to improve their attitude towards the safety of their customers (I'm thinking here of exploding Ford Pintos and similar products) so maybe it is not all bad news. Regards, Keith Armstrong In a message dated 03/01/02 05:33:20 GMT Standard Time, m...@california.com writes: Subj:Re: EMC-related safety issues Date:03/01/02 05:33:20 GMT Standard Time From:m...@california.com (Robert Macy) Sender:owner-emc-p...@majordomo.ieee.org Reply-to: A HREF=mailto:m...@california.com;m...@california.com/A (Robert Macy) To:gary.mcintu...@worldwidepackets.com (Gary McInturff), ken.ja...@emccompliance.com (Ken Javor), cherryclo...@aol.com Great, Now we have to start adding information on the sales brochure, like As the purchaser of this product places this product into service said purchase is forming a licensed arrangement with the vendor to not hold said vendor culpable for all uses and potential misuses of this product You get the drift, just copy the MS licensing language on all software. - Robert - Robert A. Macy, PEA HREF=mailto:m...@california.com;m...@california.com/A 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message- From: Gary McInturff A HREF=mailto:gary.mcintu...@worldwidepackets.com;gary.mcintu...@worldwidepackets.com/A To: Ken Javor A HREF=mailto:ken.ja...@emccompliance.com;ken.ja...@emccompliance.com/A; A HREF=mailto:cherryclo...@aol.com;cherryclo...@aol.com/A A HREF=mailto:cherryclo...@aol.com; cherryclo...@aol.com/A; A HREF=mailto:emc-p...@majordomo.ieee.org;emc-p...@majordomo.ieee.org/A A HREF=mailto:emc-p...@majordomo.ieee.org; emc-p...@majordomo.ieee.org/A Date: Wednesday, January 02, 2002 2:38 PM Subject: RE: EMC-related safety issues Did the camera have proximal cause to the event that befell the child, well not unless it fell of of the ceiling or the tripod fell over and hit the infant, or the camera overheated and started a fire. Other than that the Lawyers need to dig their heads out - juries as well. They are just trying to chase the money. Cameras don't cause disease likes SIDS. They don't cause buildings to collapse, or burglaries or whatever else might befall the baby They are just a convenience. If they an additional input path to the parents may stop, but the actual monitoring (or the failure of monitoring) neither helped or hindered the health of the child. The camera manufacturer, even if this is sold as a baby monitor, I can't see how holding the camera manufacturer responsible can even be considered, except that it gives the lawyers somebody to sue with some money. I suppose it might give the parents a misplaced sense of (and I hate this word) closure because they can blame some body, rather than just life, fate, or whatever. I don't doubt your statement that somebody is trying to hold the manufacturer responsible, I just point out that it is asinine and in my opinion inexcusable to do so. Recorded history doesn't show a huge plethora of infant deaths because parents weren't able to have a video camera in the room. Gary -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, January 02, 2002 11:22 AM To: cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I have read a part of the IEE guide mentioned below. What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or misuse of the equipment he sells in concert with every other type of equipment made or that might be made at some time in the future. This document is a trial lawyer's dream. It takes us from a society in which a sale was deemed a transaction of mutual benefit between equals to a society in which an Omniscient Producer must cater to the needs of an ignorant, childlike Consumer, and in direct corollary, any misuse of any product by any consumer is deemed proof that the Omniscient Producer was profiting by taking advantage of a helpless victim. I realize this document merely reflects this prevalent view, but the idea that an Industry group would provide such a smoking gun for some trial lawyer to use in defense of some poor misled swindled consumer is, to say
RE: EMC-related safety issues
Ken, I don't think anyone could disagree with your sentiments. The problem is attributing the level of liability between user and manufacturer. Car manufacturers sleep at night yet their products kill thousands each year, they design them to high standards yet by their use they still kill and maim. Do we hold them liable, no, in 99.9% of cases we don't. You slip down the stairs and break your leg, do you sue: * the caveman who invented the staircase? * your shoe manufacturer for using a shoe sole incompatible with the stair carpet? * the stair carpet manufacturer for using material incompatible with the shoe sole material? * the distiller for not putting a warning on the bottle of whisky you just drank It's reasonable responsibility/diligence that needs defining, not spurious emissions!! In addition the legal fraternity should have some standards imposed upon them to put an end to pure gold digging through litigation that seems to just escalate and to which we thus have to pander. If every foreseeable mis-use of every commodity sold was accounted for then no-one would sell anything. Chris __ Chris James Engineering Services Manager Dolby Laboratories, Inc. (UK) -Original Message- From: acar...@uk.xyratex.com [mailto:acar...@uk.xyratex.com] Sent: 03 January 2002 12:54 To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I get the idea that we a missing the whole point of this discussion. Should we as Professional Safety Engineers and Product designers consider the safety implications of EMC emissions ? The answer is a definite Yes. We have a clear duty of care and responsibility to consider all implications of our products being used in there intended application. Even if the consideration on EMC emissions and safety is Do not be silly. We still have to at least consider it. It has been stated that CISPR22 and CFR Title 47 Part 15b is only concerned with interfering with radio transmissions. This is true and why the enforcement falls under the Federal Communications Commission. But not all products fall under this remit and could quite happily be emitting large EM fields and comply with all current US legislation. Take for example the line surge equipment you use to test immunity to EN61000-4-5, exempt from the Part 15B under section 15.29 as A digital device used exclusively as industrial, commercial, or medical test equipment. And clearly not medical equipment. Yet when operated can produce a magnetic field that will interfere with the operation of old style pacemakers. Should you consider this when addressing the safe design of the product, or blindly state you meet all applicable EMC regulations for this product. With my unit the manufacturers have considered this and clearly state in the user manual that people with pacemakers should not operate or be be near the equipment when it is use. Two lines in the manual is not very big much against the risk the of killing someone. In Europe for CE we have no choice. The LVD state quite clearly that testing to a standard alone is insufficient to demonstrate compliance. You to consider foreseeable use and misuse, and you have to perform a risk assessment on your equipment. Taking it down to the standard level IEC60950 3rd Edition, section 0.2.7 states you must consider the effect of rf radiation on service and user personnel. Another example, you build a IPC cabinet for to be built into a production line, again exempt from CISPR 22, yet when it it running, causes interference on the control circuitry of a nearby Robotic arm. In the US immunity testing is not required, so who is liable. A susceptible Arm or noisy IPC cabinet. Being that every was fine until the cabinet was installed, you can see the blame would be pointed. Simply put, if EMC emissions from one of your products caused someone's death, because you did not consider it important. Could you sleep at night ? Ken Javor wrote: In my experience it is EXTREMELY unlikely that personal electronics could have disturbed ADF heading indication. The ADF sensor is an electrostatically shielded loop which is mounted typically on the belly of a transport class aircraft, well away from any passenger-conveyed intense sources of magnetic fields. The loop is very insensitive and requires quite a bit of magnetic field to respond and is completely insensitive to electric fields altogether. Further, no one would use ADF to line up an approach on a runway. -- From: Cortland Richmond cortland.richm...@alcatel.com To: Mike Hopkins mhopk...@thermokeytek.com Cc: cherryclo...@aol.com, emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Wed, Jan 2, 2002, 5:26 PM If they meant radio compass, that is a different can of monkeys. The radio compass was traditionally the indicator
RE: Field Strength - Substitution Method
Hi All, Thanks for all your input. I believe I have a better handle on it now. Kind Regards, Sam Wismer Engineering Manager ACS, Inc. Phone: (770) 831-8048 Fax: (770) 831-8598 Web: www.acstestlab.com -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of John Woodgate Sent: Friday, December 28, 2001 1:31 PM To: emc-p...@majordomo.ieee.org Subject: Re: Field Strength - Substitution Method I read in !emc-pstc that Cortland Richmond 72146@compuserve.com wrote (in 200112280904_mc3-ec2a-3...@compuserve.com) about 'Field Strength - Substitution Method', on Fri, 28 Dec 2001: This isn't the issue. The receiving antenna, as you say, can't tell. The problem is the substitute antenna. We assume the source is a dipole (or, here, a bilog) at every frequency. Our substitute antenna has a simple pattern (even a bilog - we spend a lot of money to get it, too). The source is not so simple. Even if it IS a half-wave dipole at (say) 100 MHz, at harmonics it is a wavelength long or more, and radiates in sheaves of cones oriented at some angle along the axis of the wire (a LP does NOT do this!) - most of which may miss the receiving antenna completely on an OATS. The angles along the wire decrease as the frequency increases. It will have gain over a dipole; the lobes off its ends narrower and stronger than those from a dipole fed with the same power, and at high enough harmonics, close enough to the axis of the conductor that they are again directed towards the receiving antenna as we turn the EUT. This will bias calculations which assume the source has a simple pattern at _every_ frequency. It doesn't. I just don't buy that. The receiving antenna is measuring the field strength at its position (actually some sort of average over its volume). How that field strength is produced is irrelevant - whether it comes from the bilog or the EUT. Besides, limits are based on the direct measurement of field strength by a receiving antenna. Only the changes of height and polarization search the actual emission pattern of the EUT, with a VERY broad brush. Emissions in narrow lobes in other directions and emissions at harmonic frequencies are not measured, but that is not an error - they are either measured at another stage (higher frequency measurements or during rotation of the EUT) or are not required to be measured. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I read in !emc-pstc that Andrew Carson acar...@uk.xyratex.com wrote (in 3c345485.b0f29...@uk.xyratex.com) about 'EMC-related safety issues', on Thu, 3 Jan 2002: I get the idea that we a missing the whole point of this discussion. I think that you are missing the point. The major concern among responsible designers is that they are being expected to do the impossible - predict ALL possible scenarios and misuses that might occur, and ensure that no hazard results. Furthermore, in the event of an incident, the authorities are in the position of having to predict nothing; it is then known which of a trillion possible (however improbable) scenarios occurred, and it is then being deemed 'obvious' that the designer should have foreseen it. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EMC-related safety issues
The incident about the wheelchair going over a cliff is a documented report to the FDA. You can find it mentioned on the FDA's web site along with other reports of wheelchairs gone berserk due to EMC issues, typically with radios. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Mike Hopkins [mailto:mhopk...@thermokeytek.com] Sent: Wednesday, January 02, 2002 5:58 PM To: 'Cortland Richmond'; cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: RE: EMC-related safety issues As already stated, the incident of the DC-10 has for years been used as an example of personal electronics (laptops) interfering with avionics. The only version I've ever heard (and the only one that makes sense) had to do with interference to an ILS receiver operating somewhere between 108MHz and 118MHz. I for one, don't believe in laptop computers interfering with a compass -- UNLESS -- the people reporting the story (and writing the guide?) used a compass as a way to relate to the general population that a laptop caused interference with an instrument that kept the airplane headed in the right direction -- probably assuming that most people would not be able to relate to an ILS or NAV receiver, but everyone knows what a compass is. I remember the magazine article, which also reported on an electronically controlled wheelchair going out of control when an EMT keyed a mobile two-way radio in a nearby ambulance. (I might add, I've since heard several variations on that story as well -- wheelchair went over a cliff, wheelchair went around in circles, wheelchair dumped patient and took of by itself; radio was a walkie-talkie, radio was CB, etc You get the idea.) There was also a video being circulated of a Connie Chung news broadcast relating similar horror stories of the effects of EMC. We used to have a copy here, but I haven't seen it in years -- probably dumped when we moved. My 2 cents worth.. Mike Hopkins Thermo KeyTek -Original Message- From: Cortland Richmond [mailto:cortland.richm...@alcatel.com] Sent: Wednesday, January 02, 2002 2:56 PM To: cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues It is perhaps less than useful to depend on a third or fourth party report of an incident to justify preventive measures. The mention in the Guide, of an aircraft compass being changed ten degrees by a laptop computer, is an example of a report which needs to be more completely reported. I was disappointed not to see it followed up in the Annex. I was curious about this because I was an avionics technician for 14 years and have been in EMI since 1983 -- over 13 years of that in the computer industry -- and I've never seen that effect caused by a device such as a laptop computer, only from large magnetic fields (such as DC motors). It struck me as unlikely that an aircraft compass could be affected by a laptop. Other systems, yes, the compass, no. The citation for the referenced incident was Compliance Engineering (CE magazine), the European edition, for November/December 1996. It probably also appeared in the US edition. I contacted CE Magazine, who are looking for a copy of that issue, so I may get a copy of the article. I expect I'll end up at the Department of Transportation's Web site, once I know the exact date of the event. However, one of the list members might have in his library a copy of that issue from 1996, and can report what the article actually says. That would be a step forward. I've personally been involved with similar incidents of people using computers made by my (at the time) employers where there had been a request to turn off a laptop due to interference with aircraft navigational or communications systems. In one case, a specific frequency was reported. Yet when the computer was checked, I could find no trace of an emission anywhere near the frequency supposedly affected. Cheers, Cortland Richmond (my opinion's, not my employers') cherryclo...@aol.com wrote: I won't get into whether you were intending to impugn my truthfulness, and shall assume you just used an unfortunate turn of phrase. I had already said I was not aware of the previous communications on this issue, so I could not have been aware that you were restricting the discussion to the kinds of emissions controlled by CISPR 22 and Title 47, part 15B of the US Code of Federal Regulations. I thought the concern was for spurious emissions in the wider sense of electromagnetic engineering. I don't believe that CISPR 22 (or any other European EMC standards) even mentions the term 'spurious emissions' much less defines it. Also, CISPR 22 does not control all the possible emissions from equipment that comes under its scope, for example it does not limit emissions above 1GHz as yet, or below 150kHz. Anyway, CIPSR22 and Title 47, part 15B of the US Code of Federal Regulations
RE: EMC-related safety issues
Ken, let me address the specific case you mentioned - the RF camera used for baby surveillance. In that particular application, surveillance for the protection of persons, more severe immunity requirements apply. Those requirements are either specified in EN 50130-4 or the particular ETSI product EMC standard. A manucturer should understand that the product may be used for protection of persons and apply the appropriate immunity requirements. Failure to do so, could create a liability issue. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, January 02, 2002 2:22 PM To: cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I have read a part of the IEE guide mentioned below. What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or misuse of the equipment he sells in concert with every other type of equipment made or that might be made at some time in the future. This document is a trial lawyer's dream. It takes us from a society in which a sale was deemed a transaction of mutual benefit between equals to a society in which an Omniscient Producer must cater to the needs of an ignorant, childlike Consumer, and in direct corollary, any misuse of any product by any consumer is deemed proof that the Omniscient Producer was profiting by taking advantage of a helpless victim. I realize this document merely reflects this prevalent view, but the idea that an Industry group would provide such a smoking gun for some trial lawyer to use in defense of some poor misled swindled consumer is, to say the least, troubling. To say that Industry standards don't go far enough, that it is the responsibility of the Producer to be able to determine all possible environments and failure modes that might ever occur is placing an impossible burden and any rationale entity, upon reading this document will immediately cease production of anything that could conceivably ever malfunction in anyway whatsoever. Case in point: A friend of mine bought one of these 2.4 GHz remote miniature video cameras with integral IREDs and is able to monitor his infant twins from his own bedroom, even in the middle of the night with no lights on in the twins' bedroom. Suppose that 2.4 GHz link is disturbed in some way and he misses something important happening in that bedroom. Is the manufacturer of that video system responsible for any ill that then befalls my friend's twins? I think not. But this safety guide says yes, and places the manufacturer at risk. -- From: cherryclo...@aol.com To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Wed, Jan 2, 2002, 9:49 AM Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't read) instead of simply saying what it is that you think is wrong with it. Of course I am passionate about the IEE guide - my colleagues and I spent a long time working on it! When I discovered you were criticising it to the emc-pstc of course I had to respond - but I was not (and am not) trying to defend the guide, merely trying to find out just exactly what it is that you (and your silent 'equally senior experts') don't like about it so I can get it improved. I am sorry if my wordy emails give the wrong impression - the simple fact is that I always write too much (as any editor who has had an article from me will confirm!). Once again I ask you - and everyone else in the entire EMC or Safety community world-wide - to read the IEE's guide and let me have constructive comments about how to improve it. You can easily download it for free from www.iee.org.uk/Policy/Areas/Electro (- you only need to download the 'core' document for this exercise and can leave the nine 'industry annexes' for later criticism). I'll make it easy for anyone to comment even if they haven't read the Core of the IEE's guide ...the guide is based on the following engineering approach, explicitly stated at the start of its Section 4 and duplicated below. * To control EMC correctly for functional safety reasons, hazard and risk assessments must take EM environment, emissions, and immunity into account. The following should be addressed: 1) The EM disturbances, however infrequent, to which the apparatus might be exposed 2) The foreseeable effects of such disturbances on the apparatus 3) How EM disturbances emitted by the apparatus might affect other apparatus (existing or planned)? 4) The foreseeable safety implications of the above mentioned disturbances (what is the severity of the hazard, the scale of the risk, and the appropriate safety integrity level?) 5) The level
EMC for cardio : wich standard apply?
hello, I have to test an electrocardiograph for EMC , but I'm in trouble with the standard to apply. There is IEC 60601-2-25 -A1, Particular requirements for the safety of elecrocardiographs, that deals with EMC, and refers to IEC 60601-1-2 1st ed.(1993, now superseded) and is still valid, as far as I know. But now we have the new edition of IEC 60601-1-2, and its requirements are very different from 60601-2-25-A1 ones. The old edition is replaced by the new one, but what about those particular standards based on it? So I don't know which standard I have to apply. Can anybody out of there dispel my doubts? Best regards p.p. - ESAOTE S.p.A. Paolo Peruzzi Research Product DevelopmentDesign Quality Control Via di Caciolle,15tel:+39.055.4229306 I- 50127 Florence fax:+39.055.4223305 e-mail: paolo.peru...@esaote.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Electric Shock and Water
No risk of electric shock at these voltages. But in salt water environments, a greatly increased risk of corrosion. Which could in turn lead to a shock or fire hazard. Slightly off topic, but a valid point to be considered. Peter Merguerian wrote: Jason, Please explain to your colleague that for North American requirements (as depicted in the NEC and CEC) there is no risk of electric shock or fire from circuits in wet locations for up to 21.2 V. For higher voltages you should start taking steps to minimize the risk of water ingress and the risk of a person coming in touch with the circuits. In Europe, I believe the voltage level is somehat lower; if I recall correctly, 15 V. Someone correct me if I am wrong! This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 -Original Message- From: jasonxmall...@netscape.net [mailto:jasonxmall...@netscape.net] Sent: Thursday, January 03, 2002 12:57 AM To: emc-p...@majordomo.ieee.org Subject: Electric Shock and Water My apologies if this is just too naive... I am trying to explain to a collegue why there are so many cautions against mixing water with electricity. He is not the type to accept common sense as an answer. This is what I have reasoned so far... MAL-OPERATION Water is generally conductive. If it enters the area of a chassis that houses control elements such as relays or switches, it can short circuit the control elements and cause the affected device to operate unexpectedly, and sometimes in unexpected ways. ENERGIZING SURFACES Water is generally conductive. If it enters a chassis containing hazardous voltages it is possible it may act as a conductor of the voltage to an otherwise un-energized conductive surface. If the conductive surface, for whatever reason, is itself not sufficiently grounded, it can carry hazardous voltage potentials. INCREASED LEAKAGE CURRENTS Water is generally conductive. If you are working on a chassis and accidentally touch an energized contact, you may not experience any shock because there is no current path between you and the voltage source supplying the contact. Let us assume the contact is energized by a local AC mains. There is always SOME leakage current possible from where you are standing back to a grounded point. Usually it is a very small leakage. However, if you are standing in water, the leakage current is likely to be much higher, and you may experience a serious electric shock from your accidental touching of a contact. AVALANCHE EFFECT Water is generally conductive. If it enters a chassis with high power electrical components, it can instigate an avalanche of failure that results in the release of a lot of energy. For example, the water can provide a short circuit between two potentials. As it carries current, the water may heat up quite rapidly, in doing so it creates steam. The effects of the heat and steam may then provide an even lower resistance path for additional current flow...and so an avalanche of conductivity (from less conductive to more conductive) is started... I welcome any comments and additional generic scenarios. Regards, Jason Mallory Product Safety Consultant. -- __ Your favorite stores, helpful shopping tools and great gift ideas. Experience the convenience of buying online with Shop@Netscape! http://shopnow.netscape.com/ Get your own FREE, personal Netscape Mail account today at http://webmail.netscape.com/ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list.
Re: EMC-related safety issues
I get the idea that we a missing the whole point of this discussion. Should we as Professional Safety Engineers and Product designers consider the safety implications of EMC emissions ? The answer is a definite Yes. We have a clear duty of care and responsibility to consider all implications of our products being used in there intended application. Even if the consideration on EMC emissions and safety is Do not be silly. We still have to at least consider it. It has been stated that CISPR22 and CFR Title 47 Part 15b is only concerned with interfering with radio transmissions. This is true and why the enforcement falls under the Federal Communications Commission. But not all products fall under this remit and could quite happily be emitting large EM fields and comply with all current US legislation. Take for example the line surge equipment you use to test immunity to EN61000-4-5, exempt from the Part 15B under section 15.29 as A digital device used exclusively as industrial, commercial, or medical test equipment. And clearly not medical equipment. Yet when operated can produce a magnetic field that will interfere with the operation of old style pacemakers. Should you consider this when addressing the safe design of the product, or blindly state you meet all applicable EMC regulations for this product. With my unit the manufacturers have considered this and clearly state in the user manual that people with pacemakers should not operate or be be near the equipment when it is use. Two lines in the manual is not very big much against the risk the of killing someone. In Europe for CE we have no choice. The LVD state quite clearly that testing to a standard alone is insufficient to demonstrate compliance. You to consider foreseeable use and misuse, and you have to perform a risk assessment on your equipment. Taking it down to the standard level IEC60950 3rd Edition, section 0.2.7 states you must consider the effect of rf radiation on service and user personnel. Another example, you build a IPC cabinet for to be built into a production line, again exempt from CISPR 22, yet when it it running, causes interference on the control circuitry of a nearby Robotic arm. In the US immunity testing is not required, so who is liable. A susceptible Arm or noisy IPC cabinet. Being that every was fine until the cabinet was installed, you can see the blame would be pointed. Simply put, if EMC emissions from one of your products caused someone's death, because you did not consider it important. Could you sleep at night ? Ken Javor wrote: In my experience it is EXTREMELY unlikely that personal electronics could have disturbed ADF heading indication. The ADF sensor is an electrostatically shielded loop which is mounted typically on the belly of a transport class aircraft, well away from any passenger-conveyed intense sources of magnetic fields. The loop is very insensitive and requires quite a bit of magnetic field to respond and is completely insensitive to electric fields altogether. Further, no one would use ADF to line up an approach on a runway. -- From: Cortland Richmond cortland.richm...@alcatel.com To: Mike Hopkins mhopk...@thermokeytek.com Cc: cherryclo...@aol.com, emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Wed, Jan 2, 2002, 5:26 PM If they meant radio compass, that is a different can of monkeys. The radio compass was traditionally the indicator for the ADF set , pointing to the ground station, and was usually mounted so as to revolve in front of a scale which rotated with the aircraft's' magnetic heading. A noisy switching power supply could well interfere with a low-frequency receiver. But (in MY opinion) the Guide does not say enough about what actually happened. Cortland (My thoughts, not Alcatel's!) Mike Hopkins wrote: As already stated, the incident of the DC-10 has for years been used as an example of personal electronics (laptops) interfering with avionics. The only version I've ever heard (and the only one that makes sense) had to do with interference to an ILS receiver operating somewhere between 108MHz and 118MHz. I for one, don't believe in laptop computers interfering with a compass -- UNLESS -- the people reporting the story (and writing the guide?) used a compass as a way to relate to the general population that a laptop caused interference with an instrument that kept the airplane headed in the right direction -- probably assuming that most people would not be able to relate to an ILS or NAV receiver, but everyone knows what a compass is. I remember the magazine article, which also reported on an electronically controlled wheelchair going out of control
Re: Electric Shock and Water
If you work at a site with a large air conditioning plant or a chilled water system, then chances are your facilities manager will have a conductivity cell. They are used as a very quick means to monitor water purity and to check for signs of corrosion. Units are expressed in uS/cm and technically pure water is non conductive. In reality all water will contain conductive ions as soon as it is exposed to CO2 in the atmosphere. The higher the impurity of the water, the more ions available and the higher the conductivity. Typical example values would be, Ultra Pure water 1 uS/cm De Ionized Water 10uS/cm Drinking water 500-1200uS/cm Salt Water 5000-10,000uS/cm Water temperature is also plays a big factor, higher temp, again more ions, to higher conductivity. John Woodgate wrote: I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 200201030028.qaa08...@epgc264.sdd.hp.com) about 'Electric Shock and Water', on Wed, 2 Jan 2002: Is there a value (or range of values) for the resistance of water? The data exists; it depends, of course, on solute nature and concentration. Try a web search. Is there a standard way of measuring the resistance of water? Yes; a conductivity cell. An apparently simple device that isn't. Once again, a web search will probably disclose more than you ever wanted to know. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. -- Andrew Carson - Product Safety Engineer, Xyratex, UK Phone: +44 (0)23 9249 6855 Fax: +44 (0)23 9249 6014 --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Electric Shock and Water
Jason, Please explain to your colleague that for North American requirements (as depicted in the NEC and CEC) there is no risk of electric shock or fire from circuits in wet locations for up to 21.2 V. For higher voltages you should start taking steps to minimize the risk of water ingress and the risk of a person coming in touch with the circuits. In Europe, I believe the voltage level is somehat lower; if I recall correctly, 15 V. Someone correct me if I am wrong! This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail message in error, please return by forwarding the message and its attachments to the sender. PETER S. MERGUERIAN Technical Director I.T.L. (Product Testing) Ltd. 26 Hacharoshet St., POB 211 Or Yehuda 60251, Israel Tel: + 972-(0)3-5339022 Fax: + 972-(0)3-5339019 Mobile: + 972-(0)54-838175 -Original Message- From: jasonxmall...@netscape.net [mailto:jasonxmall...@netscape.net] Sent: Thursday, January 03, 2002 12:57 AM To: emc-p...@majordomo.ieee.org Subject: Electric Shock and Water My apologies if this is just too naive... I am trying to explain to a collegue why there are so many cautions against mixing water with electricity. He is not the type to accept common sense as an answer. This is what I have reasoned so far... MAL-OPERATION Water is generally conductive. If it enters the area of a chassis that houses control elements such as relays or switches, it can short circuit the control elements and cause the affected device to operate unexpectedly, and sometimes in unexpected ways. ENERGIZING SURFACES Water is generally conductive. If it enters a chassis containing hazardous voltages it is possible it may act as a conductor of the voltage to an otherwise un-energized conductive surface. If the conductive surface, for whatever reason, is itself not sufficiently grounded, it can carry hazardous voltage potentials. INCREASED LEAKAGE CURRENTS Water is generally conductive. If you are working on a chassis and accidentally touch an energized contact, you may not experience any shock because there is no current path between you and the voltage source supplying the contact. Let us assume the contact is energized by a local AC mains. There is always SOME leakage current possible from where you are standing back to a grounded point. Usually it is a very small leakage. However, if you are standing in water, the leakage current is likely to be much higher, and you may experience a serious electric shock from your accidental touching of a contact. AVALANCHE EFFECT Water is generally conductive. If it enters a chassis with high power electrical components, it can instigate an avalanche of failure that results in the release of a lot of energy. For example, the water can provide a short circuit between two potentials. As it carries current, the water may heat up quite rapidly, in doing so it creates steam. The effects of the heat and steam may then provide an even lower resistance path for additional current flow...and so an avalanche of conductivity (from less conductive to more conductive) is started... I welcome any comments and additional generic scenarios. Regards, Jason Mallory Product Safety Consultant. -- __ Your favorite stores, helpful shopping tools and great gift ideas. Experience the convenience of buying online with Shop@Netscape! http://shopnow.netscape.com/ Get your own FREE, personal Netscape Mail account today at http://webmail.netscape.com/ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Heald
Re: EMC-related safety issues
In my experience it is EXTREMELY unlikely that personal electronics could have disturbed ADF heading indication. The ADF sensor is an electrostatically shielded loop which is mounted typically on the belly of a transport class aircraft, well away from any passenger-conveyed intense sources of magnetic fields. The loop is very insensitive and requires quite a bit of magnetic field to respond and is completely insensitive to electric fields altogether. Further, no one would use ADF to line up an approach on a runway. -- From: Cortland Richmond cortland.richm...@alcatel.com To: Mike Hopkins mhopk...@thermokeytek.com Cc: cherryclo...@aol.com, emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues List-Post: emc-pstc@listserv.ieee.org Date: Wed, Jan 2, 2002, 5:26 PM If they meant radio compass, that is a different can of monkeys. The radio compass was traditionally the indicator for the ADF set , pointing to the ground station, and was usually mounted so as to revolve in front of a scale which rotated with the aircraft's' magnetic heading. A noisy switching power supply could well interfere with a low-frequency receiver. But (in MY opinion) the Guide does not say enough about what actually happened. Cortland (My thoughts, not Alcatel's!) Mike Hopkins wrote: As already stated, the incident of the DC-10 has for years been used as an example of personal electronics (laptops) interfering with avionics. The only version I've ever heard (and the only one that makes sense) had to do with interference to an ILS receiver operating somewhere between 108MHz and 118MHz. I for one, don't believe in laptop computers interfering with a compass -- UNLESS -- the people reporting the story (and writing the guide?) used a compass as a way to relate to the general population that a laptop caused interference with an instrument that kept the airplane headed in the right direction -- probably assuming that most people would not be able to relate to an ILS or NAV receiver, but everyone knows what a compass is. I remember the magazine article, which also reported on an electronically controlled wheelchair going out of control when an EMT keyed a mobile two-way radio in a nearby ambulance. (I might add, I've since heard several variations on that story as well -- wheelchair went over a cliff, wheelchair went around in circles, wheelchair dumped patient and took of by itself; radio was a walkie-talkie, radio was CB, etc You get the idea.) There was also a video being circulated of a Connie Chung news broadcast relating similar horror stories of the effects of EMC. We used to have a copy here, but I haven't seen it in years -- probably dumped when we moved.My 2 cents worth..Mike HopkinsThermo KeyTek --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
cable discharge measurements
Hi All, I have seen some postings recently on the technical lists on cable discharge so I decided to do a few measurements using a simple test setup. Cable discharge happens when a cable becomes statically charged and then is connected to equipment. This can happen by dragging a cable on the floor or just holding in in your hand as you plug it into equipment. Lately there have been reports of damage from this effect to computer interface circuits. This month's Technical Tidbit on http://www.dsmith.org presents the results of measurements on a simplified form of cable discharge. The data shows high peak currents and high di/dt values as well. The test setup is simple to make and is useful for other measurements as well. A similar test setup was used for the Technical Tidbit on measuring inductor performance at: http://www.dsmith.org/tt050100.htm Doug -- --- ___ _ Doug Smith \ / ) P.O. Box 1457 = Los Gatos, CA 95031-1457 _ / \ / \ _ TEL/FAX: 408-356-4186/358-3799 / /\ \ ] / /\ \ Mobile: 408-858-4528 | q-( ) | o |Email: d...@dsmith.org \ _ /]\ _ / Website: http://www.dsmith.org --- --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Touch-Pad ESD immunity
I read in !emc-pstc that Gary McInturff Gary.McInturff@worldwidepackets .com wrote (in 917063bab0ddb043af5faa73c7a835d40c0...@windlord.wwp.com ) about 'Touch-Pad ESD immunity', on Wed, 2 Jan 2002: Do you have denounce circuitry on the input of the touch pad The spell-checker demon strikes again! (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Electric Shock and Water
I read in !emc-pstc that Rich Nute ri...@sdd.hp.com wrote (in 200201030028.qaa08...@epgc264.sdd.hp.com) about 'Electric Shock and Water', on Wed, 2 Jan 2002: Is there a value (or range of values) for the resistance of water? The data exists; it depends, of course, on solute nature and concentration. Try a web search. Is there a standard way of measuring the resistance of water? Yes; a conductivity cell. An apparently simple device that isn't. Once again, a web search will probably disclose more than you ever wanted to know. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Electric Shock and Water
I read in !emc-pstc that jasonxmall...@netscape.net wrote (in 738426ed.4080ead3.73ea6...@netscape.net) about 'Electric Shock and Water', on Wed, 2 Jan 2002: INCREASED LEAKAGE CURRENTS Water is generally conductive. If you are working on a chassis and accidentally touch an energized contact, you may not experience any shock because there is no current path between you and the voltage source supplying the contact. Let us assume the contact is energized by a local AC mains. There is always SOME leakage current possible from where you are standing back to a grounded point. Usually it is a very small leakage. However, if you are standing in water, the leakage current is likely to be much higher, and you may experience a serious electric shock from your accidental touching of a contact. I think this lacks clarity. I suggest that you explain that you don't get a shock in the first case because your footwear is non-conducting. But if your feet are wet, there is a conducting path from them to ground AND you don't even have the limited protection afforded by the resistance of dry skin. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Quasi-Peak Measurements with Spectrum Analyzer WAS: Books about Spectrum Analyzer
I read in !emc-pstc that J.Feldhaar j.feldh...@telejet.de wrote (in 3c333461.7f5b...@telejet.de) about 'Quasi-Peak Measurements with Spectrum Analyzer WAS: Books about Spectrum Analyzer', on Wed, 2 Jan 2002: I am currently writing a book about the subject of RF spectrum analysis, which will be ready within the next 3 months. I started more than four years ago, and now I have 322 pages and more than 250 drawings. I cover the applications, theory and circuits used in five decades of spectrum analysis. There is also a chapter where some practical measurements are shown in some detail, including screenshots and so on. It sounds interesting. Unfortunately --- (always a setback) --- it is in German I can read technical German, with some difficulty. I don't know if there is a widespread demand for such a book, I began writing because I couldn't find almost no information via Internet, and also the great HP appnote 150 is not available any more. I'll be interested in your feedback I think such a book would be useful. I have technical information on the Rohde Schwartz 'Polyskop III' SWOB and on the HP 8554/8552/141T combination, if it is of any interest. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I read in !emc-pstc that Mike Hopkins mhopk...@thermokeytek.com wrote (in 49CD487E8BA9D31181190060081C6B8F3BEC1D@COMSERVER) about 'EMC- related safety issues', on Wed, 2 Jan 2002: As already stated, the incident of the DC-10 has for years been used as an example of personal electronics (laptops) interfering with avionics. The only version I've ever heard (and the only one that makes sense) had to do with interference to an ILS receiver operating somewhere between 108MHz and 118MHz. That is much more likely. It has been known for very many years that many ILS receivers have the selectivity of a wet lettuce. I have heard that many have a broadband input stage, just like a $10 FM portable. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I read in !emc-pstc that Gary McInturff Gary.McInturff@worldwidepackets .com wrote (in 917063bab0ddb043af5faa73c7a835d40ac...@windlord.wwp.com ) about 'EMC-related safety issues', on Wed, 2 Jan 2002: Cameras don't cause disease likes SIDS. Please post your proof! That is the attitude of some (too many) safety experts these days. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I read in !emc-pstc that cherryclo...@aol.com wrote (in 125.99b6ace.296 48...@aol.com) about 'EMC-related safety issues', on Wed, 2 Jan 2002: I understand that under European Product Liability law (and I suspect in US product liability law too) evidence of a historical lack of safety problems is not considered sufficient proof that a design is as safe as people generally have the right to expect. This is another aspect of the 'culture of blame' that has grown up. Something operates without any problem for five years in the field. Suddenly, it is blamed for some incident. Obviously, then the manufacturer must have been negligent, indeed criminally negligent. He should have foreseen every possible scenario, including 'foreseeable misuse', and what is not 'foreseeable' with the 20-20 vision of hindsight? Is it foreseeable that someone gets their PDA wet and tries to dry it in a microwave oven, causing the battery to explode? Undoubtedly, because I have just foreseen it. OK, from this instant, all PDAs have to be redesigned to eliminate this hazard. Oh, and recall all products in the field, too! Or will yet another warning label be sufficient? In all official languages of the EU, of course. Where is the burden of proof of responsibility to be tested in such a case? It could well be in a TV interview, I suspect, not a courtroom. We had such cases in the 1970s, where TV sets were blamed by fire officers for house fires within a few hours of the incidents, long before any forensic investigation had determined the real cause. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: Touch-Pad ESD immunity
Well, one of the less obvious things is what does your system do to detect a true mouse pad contact? Do you have denounce circuitry on the input of the touch pad (or keyboard lines), do you sample a couple of times to see if the input stays there (thumbs are still much slower than ESD pulses). If the touch pad does provide a ground path for the ESD currents how does your equipment handle that current to insured it doesn't get into your electronics? The touch pad can certainly be the culprit and about the only way to tell is buy physically examining the pad to see how they are grounding things and using your judgment to see if its adequate. But even a well done touch pad can appear to be a problem if you have not protected the input lines, or checked for hung input states etc. Over time, touch pads also become more sensitive to the intended tapping function. After a few months I have to use and run a program that suppresses taps altogether. If I don't and the mouse pointer happens to be over the send button, for example, I will often get partially completed e-mails sent out when the old fat thumbs happen to lightly touch the touch pad itself. Telling the prospective vendor that you won't be using their touch pad and why, may offer some relief as well. Even if it does look at how well you are protecting your system from the vagrancies of ESD from the pad or a keyboard. Considering what keyboards and touch pads sell for you won't find those folks putting a whole bunch of money into hardening them. Good luck Gary -Original Message- From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Wednesday, January 02, 2002 1:47 PM To: EMC-PSTC Internet Forum Subject: Touch-Pad ESD immunity Dear Ann Landers, I've always had trouble with peripherals. Keyboards and mice that were CE marked and looked like such good prospects have mostly turned out to be fickle. Well, I've been involved with a touchpad for about five months now. When I first bought it, we were so happy. Whenever we were together it, it could read my mind. A tap of my finger and it knew just what to do. And then this ESD gun comes along. One zap and BOOM! The touchpad turns its back on me. It won't respond at all! I tried talking to it...but it just gave me the cold shoulder. I suggested counseling...still no response. I threatend to go and get a mouse...no response. Well, I finally had to just take a deep breath and go through with it. I cycled power. Well it now responds to me... but I don't know if I'll ever trust it around an ESD gun again. I don't know if our relationship will ever be the same. Signed Out of touch in New York OK OK The real question is... does anybody have some words of advice regarding touchpads. I am testing a unit which consists of a keyboard/touchpad combination. The touchpad is approx 1.5 x 1.5 and is able to sense a sliding or tapping finger. The touchpad is used to perform all of the functions that a mouse typically performs. I am assuming that it has some sort of capacitive sense circuit which can tell when your finger slides across the pad or taps on the pad. I have one that gets all out of whack with 8KV ESD. i.e. the touchpad becomes unresponsive and it stops software execution in our host system. Unfortunately, this is one of those instances where we don't build the keyboard/touchpad; so my bag of fix tricks is limited. Probably limited to seeing if another manufacturer produces a keyboard/touchpad with better performance. Or, am I slamming my head against the wall on this one? The keyboard/touchpad is already CE marked by its manufacturer. Is this typical? Are all touchpads (even CE marked ones) ESD sensitive? Do I just live with it? Am I over-testing this touchpad? Overall... I have had REALLY bad experiences with CE marked keyboards and mouses. Now I have trouble with our first touchpad. We typically use a capacitive filter on our inputs and we typically put a ferrite on the cable...yet still trouble. Is this typical of what others see? Any words of advice, experience... would be appreciated. Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher:
Re: EMC-related safety issues
Great, Now we have to start adding information on the sales brochure, like As the purchaser of this product places this product into service said purchase is forming a licensed arrangement with the vendor to not hold said vendor culpable for all uses and potential misuses of this product You get the drift, just copy the MS licensing language on all software. - Robert - Robert A. Macy, PEm...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -Original Message- From: Gary McInturff gary.mcintu...@worldwidepackets.com To: Ken Javor ken.ja...@emccompliance.com; cherryclo...@aol.com cherryclo...@aol.com; emc-p...@majordomo.ieee.org emc-p...@majordomo.ieee.org Date: Wednesday, January 02, 2002 2:38 PM Subject: RE: EMC-related safety issues Did the camera have proximal cause to the event that befell the child, well not unless it fell of of the ceiling or the tripod fell over and hit the infant, or the camera overheated and started a fire. Other than that the Lawyers need to dig their heads out - juries as well. They are just trying to chase the money. Cameras don't cause disease likes SIDS. They don't cause buildings to collapse, or burglaries or whatever else might befall the baby They are just a convenience. If they an additional input path to the parents may stop, but the actual monitoring (or the failure of monitoring) neither helped or hindered the health of the child. The camera manufacturer, even if this is sold as a baby monitor, I can't see how holding the camera manufacturer responsible can even be considered, except that it gives the lawyers somebody to sue with some money. I suppose it might give the parents a misplaced sense of (and I hate this word) closure because they can blame some body, rather than just life, fate, or whatever. I don't doubt your statement that somebody is trying to hold the manufacturer responsible, I just point out that it is asinine and in my opinion inexcusable to do so. Recorded history doesn't show a huge plethora of infant deaths because parents weren't able to have a video camera in the room. Gary -Original Message- From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, January 02, 2002 11:22 AM To: cherryclo...@aol.com; emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues I have read a part of the IEE guide mentioned below. What I have read on a paragraph by paragraph basis is fine, but I find the overall philosophy deeply troubling. The tone of the document is that the manufacturer is responsible for all uses or misuse of the equipment he sells in concert with every other type of equipment made or that might be made at some time in the future. This document is a trial lawyer's dream. It takes us from a society in which a sale was deemed a transaction of mutual benefit between equals to a society in which an Omniscient Producer must cater to the needs of an ignorant, childlike Consumer, and in direct corollary, any misuse of any product by any consumer is deemed proof that the Omniscient Producer was profiting by taking advantage of a helpless victim. I realize this document merely reflects this prevalent view, but the idea that an Industry group would provide such a smoking gun for some trial lawyer to use in defense of some poor misled swindled consumer is, to say the least, troubling. To say that Industry standards don't go far enough, that it is the responsibility of the Producer to be able to determine all possible environments and failure modes that might ever occur is placing an impossible burden and any rationale entity, upon reading this document will immediately cease production of anything that could conceivably ever malfunction in anyway whatsoever. Case in point: A friend of mine bought one of these 2.4 GHz remote miniature video cameras with integral IREDs and is able to monitor his infant twins from his own bedroom, even in the middle of the night with no lights on in the twins' bedroom. Suppose that 2.4 GHz link is disturbed in some way and he misses something important happening in that bedroom. Is the manufacturer of that video system responsible for any ill that then befalls my friend's twins? I think not. But this safety guide says yes, and places the manufacturer at risk. -- From: cherryclo...@aol.com To: emc-p...@majordomo.ieee.org Subject: Re: EMC-related safety issues Date: Wed, Jan 2, 2002, 9:49 AM Once again, John, you seem to be trying to give a negative impression about the IEE's guide on EMC and Functional Safety (which you now admit you haven't
RE: Electric Shock and Water
Water, as is generally conductive, forms a better surface contact ( to you), reducing the surface resistivity (yours), thus allowing a greater flow of lethal current through the body (yours) from an energised electrical device. And when coupled with any, or all of the previous faults, you may kiss it good-by, or expect to spend a long vacation in the burn unit of your local hospital. John Shinn, P.E. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of jasonxmall...@netscape.net Sent: Wednesday, January 02, 2002 2:57 PM To: emc-p...@majordomo.ieee.org Subject: Electric Shock and Water My apologies if this is just too naive... I am trying to explain to a collegue why there are so many cautions against mixing water with electricity. He is not the type to accept common sense as an answer. This is what I have reasoned so far... MAL-OPERATION Water is generally conductive. If it enters the area of a chassis that houses control elements such as relays or switches, it can short circuit the control elements and cause the affected device to operate unexpectedly, and sometimes in unexpected ways. ENERGIZING SURFACES Water is generally conductive. If it enters a chassis containing hazardous voltages it is possible it may act as a conductor of the voltage to an otherwise un-energized conductive surface. If the conductive surface, for whatever reason, is itself not sufficiently grounded, it can carry hazardous voltage potentials. INCREASED LEAKAGE CURRENTS Water is generally conductive. If you are working on a chassis and accidentally touch an energized contact, you may not experience any shock because there is no current path between you and the voltage source supplying the contact. Let us assume the contact is energized by a local AC mains. There is always SOME leakage current possible from where you are standing back to a grounded point. Usually it is a very small leakage. However, if you are standing in water, the leakage current is likely to be much higher, and you may experience a serious electric shock from your accidental touching of a contact. AVALANCHE EFFECT Water is generally conductive. If it enters a chassis with high power electrical components, it can instigate an avalanche of failure that results in the release of a lot of energy. For example, the water can provide a short circuit between two potentials. As it carries current, the water may heat up quite rapidly, in doing so it creates steam. The effects of the heat and steam may then provide an even lower resistance path for additional current flow...and so an avalanche of conductivity (from less conductive to more conductive) is started... I welcome any comments and additional generic scenarios. Regards, Jason Mallory Product Safety Consultant. -- __ Your favorite stores, helpful shopping tools and great gift ideas. Experience the convenience of buying online with Shop@Netscape! http://shopnow.netscape.com/ Get your own FREE, personal Netscape Mail account today at http://webmail.netscape.com/ --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: Electric Shock and Water
Hi Jason: Water comprises a 3-dimensional resistor. The value of the resistor depends on: * the purity of the water itself (the resistance is inversely proportional to the purity); * the dimensions of the electrodes (i.e., the conductors in contact with the water); * the distance between the two electrodes; * the cross-sectional dimensions of the current pathway; * other conductors in the water (which may short out some of the water, or may carry some of the current to another load). The hazard of water is that it displaces air insulation in typical electrical products. Most products rely on air insulation for both performance and protection against electric shock (which is why safety standards include minimum dimensions for clearance). If water displaces the air insulation, then an unintended current path is created. If the body happens to touch that water, then the unintended current path may include the body. If your colleague understands that air is commonly employed as an electrical insulator (e.g., overhead power lines), then I would hope that he could understand that water displaces the air, and thereby provides an unintended (and uncontrolled) conductive path. (Most of your examples are examples of water displacing air insulation.) Water on the skin tends to enlarge the electrical connection to the body. The larger the area of electrical connection to the body, the more susceptible the body is to the same value of current. (This explains your leakage paragraph.) Best regards, Rich ps: Is there a value (or range of values) for the resistance of water? Is there a standard way of measuring the resistance of water? --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
