RE: NEAR/ FAR FIELD CORRELATION ISSUES
At the AST research location in Irvine, California, there exists what I believe may be the only commercially deployed bipolar gigahertz field chamber. This is a patented design by Dr. Andrew Podgorsky, in this case conversion of an existing, small, semi-anechoic chamber to a form of TEM cell in which uniform fields can be accurately generated over a relatively large volume. The corollary to this is, fields can be accurately measured in the at volume, and Jozef Baran, leader of the EMC group at AST, who had this built, was able to obtain FCC recognition as equivalent to an open-air test site. If you want more information on this device, look in the annual IEEE EMC Symposium papers. Search on the inventor, Andrew Podgorski, the term "BGF", and for the installation at AST on the names Jozef Baran, and Mark Frankfurth. I had the great good fortune to work at AST while the BGF chamber was being installed, and to later see the final configuration after all testing and tweaking had been completed. While not a compete replacement for open air sites -- there IS a volume limitation -- it seems to me for for desktop and laptop computers to offer not only the promise of accurate readings without ambients, but also the possibility of automating testing (if a standard peripheral and cable configuration can be agreed on as satisfactory). Cortland Richmond == Original Message Follows >> Date: 18-Jun-99 15:28:05 MsgID: 1068-84459 ToID: 72146,373 From: Gary McInturff >INTERNET:gmcintu...@packetengines.com Subj: RE: NEAR/ FAR FIELD CORRELATION ISSUES Chrg: $0.00 Imp: Norm Sens: StdReceipt: NoParts: 1 The closest thing I have heard about was a claim by one of Chris Kendall's engineers that he could get correlatible data between a small ferrite shielded room and an OATS site. It did however, have to develop and antenna height factor, if you will. The room is roughly 10 by 12 by 20 feet (for Europe that's about as useful as furlongs per fortnight but anyway...) The biggest problem was the inability to raise the antenna. With some mathematically trickery they were able to apply this factor and claimed to be within a dB of the actual OATs measurement. The article didn't describe the complexity of the equipment under test so there could be a whole raft of problems there, and you would have to be of the short that believes that the FCC 3 meter testing is valid and many do not. The good news is that the cost of such a chamber starts to fall more in-line with what people can afford and even more important could be put in many buildings that already exist in every city. Now at least EMC vendors could move near us, rather than we having to travel to them, plus the other benefits that such a room can bring to the table. The bad news is that they have a long way to go in convincing the appropriate people that it really works, and they still had some problems at th 30 to 60 MHz region and were looking for some acceptance of a fudge factor in this range. Before the scoffing begins at my useless optimism, I might point out that not long ago the same problems existed for the large chambers, but many of the big kids are quite happily qualifying stuff in those. It is a long shot but I would certainly wish them success if they can do it, and any start is a good start. I haven't been in touch with them lately to know of their progress. Gary -Original Message- From: Roman, Dan [SMTP:dan.ro...@dialogic.com] Sent: Friday, June 18, 1999 12:29 PM To: 'emc-p...@majordomo.ieee.org' Subject:RE: NEAR/ FAR FIELD CORRELATION ISSUES I also have been following this thread with interest, but even more practical and technically less challenging alternate methods of testing take too long for acceptance in my opinion. Forget near-field measurements with probes, I'd like to see quicker movement on acceptance of standards like EN50147-3 for fully anechoic compact chambers. I'm not going to get greedy and look for (or expect) near field or cable clamp measurement acceptance in the near future. Since I mentioned it, does anyone know if there is movement or progress in the area of standards tailored specifically for compact chambers like EN50147-3? -- Dan Roman, Compliance Engineer * mailto:dan.ro...@dialogic.com *Voice: +1 (973) 993-3000 ext. 6485 Fax: +1 (973) 993-8466 - 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, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators). - This message i
Fully Anechoic Chambers (was NEAR/ FAR FIELD CORRELATION ISSUES)
The single most biggest problem with a fully anechoic chamber with fixed antenna height as proposed by various groups, is, the inability to detect directed beam emissions especially at higher frequencies (over 500 MHz) Such emissions are, for example, emissions out of drive bays from computers. Most EMC engineers have seen those GHz harmonic emission when processors of 400MHz and higher are used. === Best Regards Hans Mellberg EMC Consultant _ Do You Yahoo!? Get your free @yahoo.com address at http://mail.yahoo.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, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Medical Device Directive, IEC 601-1-2, and IEC 1000-3-2
Patrick, David I do not believe that David's answer is correct. Harmonised standards are harmonised within the framework of a specific Directive. As far as I know EN 60601-1-2 is the only EMC standard harmonised within the framework of the Medical Devices Directive. The EMC Directive does not apply the medical devices, so EN 61000-3-2 does not apply. Jon Griver ITL (Product Testing) Ltd. http://www.itl.co.il At 14:25 18/06/99 -0400, you wrote: > >Pat: >61000-3-2 is a horizontal standard and it applies to all products unless >specifically excluded by 61000-3-2. The criteria is defined by CENELEC and >it is not necessarily specified by the individual product standards. This >is why it is so important to watch basic and horizontal standards even >though they may not called out in the product standards. These >cross-the-board standards are sleepers and can effect manufacturer's through >the back door. > >Industry has decided to fight 61000-3-2 in the IEC and try to achieve >realistic requirements. The US national committee has just released a >position paper on harmonics requirements. If anyone needs a copy I can post >it on this net. >Dave George >Unisys > >-Original Message- >From: plaw...@west.net [mailto:plaw...@west.net] >Sent: Thursday, June 17, 1999 7:55 PM >To: emc-p...@majordomo.ieee.org >Subject: Medical Device Directive, IEC 601-1-2, and IEC 1000-3-2 > > > >I was asked the following question, and wasn't sure about the answer: > >1) A manufacturer can claim his system complies with the Medical Device >Directive by testing to EN 60601-1-2:1993. > >2) EN 60601-1-2:1993 does not have any requirements to test to IEC 1000-3-2. > >3) Does that mean that the harmonic standard does not apply to this system >when >it becomes mandatory in 2001? > > >I realize the Second Edition of IEC60601-1-2 is just around the corner, and >that edition _does_ call out the harmonic test. However, I've been told >that >it may not take effect until 2003. >-- >Patrick Lawler >plaw...@west.net > >- >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, >jim_bac...@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, >jim_bac...@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, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
New EEC Electronic Waste Legistration
Hi folks, Can anyone advise me where I can obtain the information on the new EEC electronic waste legistration to be implemented in 2002. Thanks, Raymond Li Dixons Asia Ltd. - 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, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
Re: NEAR/ FAR FIELD CORRELATION ISSUES
Ed, please send this out only if you think it's appropriate. Hi folks, I don't want to run the risk of offending list members, but what's the problem over test costs? I charge little more than the chap that repairs my car, or the guy that fixes my A/C. EMC is a part of life, live with it. I speculate that most folks will get help early, and life will be OK. Some folks may not pay up front and suffer later: this is not a new lesson. Rather than try to change test methods that work fine, even if they could be a little better, take a close look at where your facility money goes. then charge what should be charged, not what you can get away with! If anyone wants to criticize me, e-mail direct. Or call, 815 637 3729. My humble opinion, Derek Walton - 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, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
RE: Medical Device Directive, IEC 601-1-2, and IEC 1000-3-2
In message <8E37550684B3D211A20B0090271EC59D01AF1427@tr-exchange- 1.tr.unisys.com> "George, David L" writes: > Industry has decided to fight 61000-3-2 in the IEC and try to achieve > realistic requirements. The US national committee has just released a > position paper on harmonics requirements. If anyone needs a copy I can post > it on this net. > Dave George > Unisys Dave, I for one would be most interested to see this. Regards, Bill. -- Bill Lyons Claude Lyons Limited, Brook Road, Waltham Cross, Herts EN8 7LR, UK Tel: +44 1992 768 888 email: b...@lyons.demon.co.uk Fax: +44 1992 769 849 URL: http://www.claudelyons.co.uk - 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, jim_bac...@monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
