RE: Doubt on Measuring with Spectrum Analyser
try their website sara.com and look for the CASSPER system. At 08:33 AM 9/24/98 -0700, you wrote: Scientific Applications and Research Associates has a Pre-Compliance test system which is said to be able to accurately measure emissions in the presence of Ambient signals. I believe the system is Called CASSPER. For more info, Contact Ed Nakauchi (714) 903-1000 x234 Regards! Randy Flinders EMC Engineer Emulex Network Systems (714) 513-8012 randall.flind...@emulex.com -- From: Keith Armstrong Sent: Wednesday, September 23, 1998 7:35 PM To: Thomas N. Cokenias Cc: Muriel Bittencourt de Liz; emc-p...@ieee.org Subject: Re: Doubt on Measuring with Spectrum Analyser Dear all There is a UK EMC test equipment company called Laplace Instruments that claims to have done considerable work on this sort of issue, having found that A-B does not work. They have special software that uses a calibrated Comparison Noise Emitter to compensate for site variations. It may also be useful against ambients. It is a low-cost pre-compliance system and not intended for full compliance tests. I only know of it through talking to them at the IEEE show in Denver. For more info: their site is www.laplace.co.uk or you could Email David Mawdsley at t...@laplace.co.uk. Hope this helps! Keith Armstrong Partner, Cherry Clough Consultants EMC-UK Associate phone: +44 1457 871 605 Fax: +44 1457 820 145 Email: karmstr...@iee.org Thomas N. Cokenias wrote: Muriel, It depends on how you are subtracting. When measuring with EUT on, you are looking at ambient + EUT signal - in a logarithmic representation when using the analyzer log scale. Since subtracting logs is equivalent to dividing numbers, you have to be careful. A worst-case scenario is when you have an EUT signal at the same frequency as an ambient, but at only slightly lower amplitude that the ambient. I don't know of any way of extracting the EUT signal using conventional EMI instrumentation. As I recall, using the subtraction function available on most analyzers will cancel out the ambient+EUT, giving the impression there is no EUT signal there. Your task is to reduce the ambients being received by your measuring system to a level more than 6 dB below the spec limit you are measuring to, hopefully by a lot more than 6 dB. Most specifications consider a measurement valid only if signal+ambient is at least 6 dB greater than ambient alone. This way, if the EUT signal is near the limit, you will see it come and go as you turn the EUT on and off. For line conducted tests, try using an AC EMI line filter at the AC input to the LISN, placed as close as you can to the LISN. The filter should attenuate the radio signals being picked up by the mains (antenna) wires. The LISN and the filter should be mounted on the same ground plane. I have had good results in on-site tests with LISNs, filters, and a portable ground plane. If you are still measuring strong ambients in the .150-30 MHz region, you may need to take steps to shield your equipment and set-up. Best regards Tom Cokenias Consultant, EMC Radio Type Approvals - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: GOST Certificate and GOST Marking
Hello Ed, Try sending your query to i...@gost.ru (which appears on their website homepage). You can access GOST's pages (in Russian) by selecting their acronym GOST on the Safety Link www.safetylink.com Unfortunatel, their English language link does not appear to be functional yet. Regards, Art Michael * * * * * * * * * * * * * * * * * * * * * * * International Product Safety Bookshop * * Check out our current offerings! * * http://www.safetylink.com/bookshop.html * * A new service of the Safety Link * * * * * * * * * * * * * * * * * * * * * * * On Thu, 24 Sep 1998, Ed Wesel wrote: Dear EMC-PSTC Group, I am trying to get some insight about what is really needed to sell into Russia. I have heard several different approaches from distributors, sales persons and marketing types concerning compliance to The State Committee for Standardization, Metrology and Certification (Gosstandart of Russia). 1) Some say the requirement is for 1/1/99 (Certificate and marking the product) others say 7/1/98 (for Certificate). 2) Some say it applies to both Safety and EMC others say just EMC. 3) Some say it only applies to consumer products (not broadcast or video storage products). 4) Some say they can get an exemption (even say they have gotten them) this may be something like a local inspection/evaluation. 5) Does the operator's manual need to be in Russian? If yes see 6). 6) Seems Russia has many different languages which one(s) are acceptable? I am interested in knowing what other compliance engineers are doing or approaches they think will meet the legal requirements, if any apply. All suggestions are welcome. Thanks for your help! Ed Wesel Regulatory Compliance Tektronix Inc phone 503 627-1666 - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Provision of Work Equipment Regulations.
I am sure you are referring to The Provision and Use of Work Equipment Regulations 1992 which is part of UK law, and is published as Statutory Instrument (SI) 1992 No. 2932. It is the UK enactment of the requirements of 89/655/EEC (each EU country has to pass legislation making the requirements of directives into laws). It will be obtainable from HMSO (Her Majestys Stationery Office). I'm afraid I cannot readily find out where you can get a copy. The ISBN number is 0 11 025849 5, cost is 3.20 pounds. John Crabb, Product Safety Engineer, NCR Financial Solutions Group Ltd., Dundee, Scotland. -Original Message- From: 102 Schilke, Paul [SMTP:pschi...@advmac.com] Sent: 24 September 1998 17:47 To: 'pstc' Subject: Hello everyone, Does anyone know if there is a difference between the Provision of Work Equipment Regulations (PUWER 98) and 89/655/EEC. I have been told that they are one in the same but it appears that they are not. If they are not the same, does anyone know where I can obtain a copy of the PUWER directive? Regards, Paul Schilke Product Approvals Manager Nilfisk-Advance, Inc pschi...@nilfisk-advance.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
IEC 38 ? and Doubt on measuring w/SA
Hi all! What is the IEC 38 standard? How does it apply to a supply spec requirement AC 230 V standard voltage per IEC 38? Does it pertain to the +- input tolerance(s) or is it a safety standard? A quick search of the net shows a few references w/o detail. I am appealing again to your vast knowledge. I find as I have since I started school the more I know the more I find I don't. Or said another way the more know the more I need to know. Thanks in advance. I have been enjoying the threads lately as usual. As to the ambient how often do they really add exactly on top of the UUT. The frequency of clocks are often a skew enough that you can catch them by off and on checks of the UUT and a narrow span. That is with caution as to not damage to the SA by disconnecting the SA during the UUT off/ on cycle. Conducted emissions can be a problem as was stated if the power line is not filtered properly , as I learned trusting a precompliance LISNs line filter and connection to the Ground plane is important. But for us poor precompliance testers some times all we can do is work late of come in early. I remember one time working in my back yard 6am Sat , in the ignorant early days, in an effort to avoid ambients. I was fat dome and happy until about 9am when the cell phones hit the road on the highway about half a mile away. Not to mention the lack of a ground plane caused me to miss some broad band signals. But that was an EMC LIFE time ago. Now I have a ground plane and more experience it does take time a caution working in and around ambient signals. At times I have had to go to the engineers next door and install line filters on their test setup. Fun! Remember as an old friend, 85, said to me `enjoy every day it's the only one we have today'. Best to you all. Best regards, Terry J. Meck Senior Compliance/Test Engineer Phone:215-721-5280 Fax:215-721-5551 hard copy; Fax PC: 215.799.1650 To my desk PC tjm...@accusort.com Accu-Sort Systems Inc. 511 School House Rd. Telford, PA 18969-1196 USA - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Argenitine Follow-up
To emc-pstc group, Below is an email I just received from Ing. Osvaldo D. Petroni of IRAM. It sheds a little bit more light on the topic of Resolution 92/98. And for those of you wishing to visit IRAM's web site, put on your Spanish glasses first as that is the only way to see the sights. Scott s_doug...@ecrm.com p.s. Gads, I love this email stuff! Thanks again to Walter Fricke in Germany, Jack Schanker in New York and Osvaldo D. Petroni in Argentina for all the help putting this together. ir...@sminter.com.ar writes: Dear Mr. Douglas, I received your last two messages and I would like to thank you for sending me the file with the resultant English translation of Resolution 92/98. Probably, we are going to use this text as a basis to prepare an English version of the Resolution. Anyway, we are currently discussing with UL an agreement on co-operation in such a way that UL could act as inspection agent and/or testing agency for IRAM. Within this context, UL has nominated a group of their professionals to work specifically on Resolution 92/98 matters. As far as we know, UL has prepared a full set of documents related to this subject in English. To obtain these information please contact at UL to Mr. Jaime M. Cadena Villacres (cade...@ul.com) or Mr. Tim R. Calland (calla...@ul.com). In respect to your preliminary comments, you were right when you understood that Resolution 92/98 is similar to Low Voltage Directive in the European Union. Safety requirements detailed in Annex I of the resolution are practically the same of the Directive 73/23 of the EU. Regarding to the applicable standards, the Resolution S.I.C.M. 92/98 establishes that the Essential Safety Requirements are understood as fully satisfied if the electrical equipment satisfy the corresponding IRAM or IEC standard. Finally, regarding our organization, IRAM is the National Standardization Body of Argentina and also operates as a Certification Body for Products, Services, Quality Systems and Environmental Management. We are a non profit private association that was founded in 1935. If you are interested in knowing more about IRAM, please visit our web site at http://www.iram.com.ar. Sincerely, Ing. Osvaldo D. Petroni JEFE DPTO. ELÉCTRICA-ELECTRÓNICA DIRECCIÓN DE NORMALIZACIÓN - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Waveguide Propagation
Greetings Everyone! Can anyone provide a formula for the transmission loss of a waveguide at frequencies BELOW it's normally useful range? I would like to construct a high-pass filter to reject the fundamental frequency of a transmitter, but allow the passage of the second and higher harmonics. I am assuming a coax transmitter output, with the coax connected to a 6dB attenuator and then a coax/waveguide transition. Then a section of straight waveguide, perhaps 18 long, followed by another waveguide/coax transition. The coax would then be connected to an attenuator and a spectrum analyzer. (The purpose of the 6dB attenuator is to limit fundamental power reflected to the transmitter to a maximum of 10% of the forward power. At the fundamental, the waveguide should yield a terrible impedance discontinuity, reflecting most of the forward power.) If I choose a waveguide which would normally just support the relatively lossless transmission of the second harmonic, how many dB of loss could I expect at 1/2 the second harmonic frequency (the fundamental frequency)? The variables which I would know are the frequencies involved, the physical width and height of the waveguide, and the length of the waveguide. A second question would be what is the effect of the length of the waveguide? Do I only need to provide a certain minimum length, or will loss be strongly proportional to waveguide length? Is it possible that the coax/waveguide transitions alone will provide enough waveguide length? To give you a better perspective, imagine that a 4.5 GHz 100 Watt transmitter is connected to X-band (WR-90 guide? normally used from 8 GHz to 12.5 GHz) waveguide. What would the transmission loss be at 4.5, 5, 6, 7, 8, and 9GHz? Thanks in Advance, Ed -- Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA. USA 619-505-2780 List-Post: emc-pstc@listserv.ieee.org Date: 09/25/1998 Time: 09:29:20 -- - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: unsubscribe emc-pstc (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
