After reading John's reply to "The wisdom behind all these standards", I then read a colleague's question regarding UL 544 and leakage current. He mentioned a 50uA leakage current limit for cardiac tissue. I want to use this as an example of the wisdom behind all these standards.
At some point in time, somebody performed an experiment to determine how much leakage current is safe for cardiac tissue. This was then incorporated into the CSA standard. From that point on, people don't need to re-invent this wheel when they make medical equipment. (I for one don't want to be the guinea pig for more cardiac tissue leakage current testing!) The safety standards from IEC, UL, CSA ... are loaded with little tidbits of information that can prevent customers from getting injured or even killed. The EMC standards set limits that minimize potential problems of interference and equipment failures due to Electro-Magnetic effects. Many people look at compliance as a money drain. However, take a look at this example. How much would it cost a medical manufacturer to determine a safe cardiac tissue leakage current? How would they get permission to perform the testing? Who would they use for the guinea pigs? Would people get injured during the experimentation? They should thank God that the standard is already there. All they need to do is look it up. By using, contributing to and updating these standards; we raise everybody's quality of life by supporting the technology that makes safer, higher quality products. There is the wisdom. That is why it is worthwhile to meet the standards. We may have differing opinions regarding where the limits should be set in the standards. But, as long as the standards are there, we have a starting point for the negotiation. If you eliminate the confusion of, "which standard to meet for which country?" Then the utility of safety and EMC standards become much more apparant. There is a great deal of overlap among standards from different countries. That's why, in my opinion, a single set of worldwide standards would be an ideal that we should always support and reach for. The wisdom is there, the implementation needs work. > -----Original Message----- > From: John Juhasz [SMTP:jjuh...@fiberoptions.com] > Sent: Friday, March 24, 2000 1:27 PM > To: 'Martin Rowe (TMW)'; emc-p...@majordomo.ieee.org > Subject: RE: The wisdom behind all these standrads > > Maybe I'm reading Martin's message wrong. If I am, then I apologize. > Here's my response to Martin's message. > > Based on what I've learned (?) over the years, the intent of these > standards is to > control interference. I think this is a good thing. I don't necessarily > agree with > some of the limits imposed, but that's another discussion. > > What we must remember here, though, is that is nearly all the cases (VCCI > is a little > different, it is mandatory BY LAW to meet these standards! Whether I > believe in an EMC > standard's appropriateness or not, or whether the standards add value or > not is not an issue. > Complying with the law in order to keep my company from being fined, or > worse losing business due to blacklisting as a result of repeated > non-conformance is THE ISSUE. > > It is also worth noting that customers (at least in my case) are becoming > more > knowledgable about regulatory affairs, and often use regulatory compliance > as > a bench mark when choosing a supplier. > > These views are mine, and mine only, and do not necessarily reflect those > of > my company. > > John Juhasz > Fiber Options > Bohemia, NY > > -----Original Message----- > From: Martin Rowe (TMW) [ <mailto:m.r...@ieee.org>] > Sent: Friday, March 24, 2000 9:54 AM > To: emc-p...@majordomo.ieee.org > Subject: The wisdom behind all these standrads > > > > I've been reading messages from this list for several months, > and I see many questions about how to comply with the long list > of EMC standards. Yet, I can't recall anyone ever questioning > the appropriateness of any standard. That is, should the > standand add value to a product or to those who use it? Is it > that the EMC engineer's place is not to question the wisdom of a > standard's value, but simply to make products with those > standards, whether or not we agree with the intent of those > standards? That's not to say that these regulations are bad. > Maybe they're good because they make the world a better place > for those who use electronic products. > > Just wondering. > > ---------------------------- /\ > | Martin Rowe | / \ > | Senior Technical Editor | / \ /\ > | Test & Measurement World | / \ / \ /\ ____ > | voice 617-558-4426 |/ \ / \ / \/ > | fax 617-928-4426 | \ / \/ > | e-mail m.r...@ieee.org | \ / > | <http://www.tmworld.com> | \/ > ---------------------------- > > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > 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: > Jim Bacher: jim_bac...@mail.monarch.com > Michael Garretson: pstc_ad...@garretson.org > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
