Derek, Changing the emissions transition frequency (conducted <> radiated) to 100 MHz like you say makes sense to me, however I think some change in the conducted setup (besides just the LISN) needs to be made for repeatability, such as shorter EUT mains cables. On the topic of "spirit of the law", I had someone challenge me once on the setup I used to verify CDN impedance. I used the same impedance reference plane that I used for LISNs, which was larger than the 0.1m x 0.1m mentioned in the standard. The only reason why this person said it was wrong was because "that is what the standard says". He showed me the Schaffner calibration fixture and said it was the right size. I pointed out it wasn't, the flange was longer than 30mm (figure 7e in the standard). He then wanted to cut the fixture. :-) Bob R.
--- On Wed, 2/9/11, Derek Walton <[email protected]> wrote: From: Derek Walton <[email protected]> Subject: Re: [PSES] EUT power cord length To: "John Davies, Blackwood Labs" <[email protected]> Cc: "<[email protected]>" <[email protected]> Date: Wednesday, February 9, 2011, 6:53 AM Many thanks to all that replied. What this shows is that even when the standard addresses a requirement, labs still test different ways. I have mixed feelings on the "spirit" of the law since this depends heavily on ones experiences. I also have misgivings about deviating from the real world ( actual cable length ) since that begins to look like the mess emissions testing is. I'd be strongly in favor of moving the conducted/radiated testing transition to around the 100 MHz region and setting test distance at a standard 3 meters also. That would be for both emissions and immunity. Any organization working on something like this? Cheers Derek Walton LF Research - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://product-compliance.oc.ieee.org/ Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]>
