John, I see your point and your position. I always appreciate your input.
I assure you I am not an EMC Crusader (I love that phrase, though). In fact, I am a minimalist which gets me in trouble with the Accreditation Crusaders :) The EMC Directive, Annex II (internal production control) point #8 says, "The manufacturer must take all measures necessary to ensure that the products are manufactured in accordance with the technical documentation referred to in point 3 and with the provisions of this Directive that apply to them." Note the requirement to assure compliance of what is manufactured, not just a verification of the compliance of a golden unit. I also feel that, "All Measures Necessary" does not mean test once than blindly manufacturer forever. All I am really saying is that it would be nice to have some set guidelines for audit testing. It wouldn't have to be in a harmonized standard. For me, I could go to my superiors with some documented support for how much resources we should be spending on conformity assessment. With all the math involved in calculating Measure Uncertainty, there should be something a lot less complicated to predict how often a production product should be retested to insure compliance. The Other Brian From: [email protected] [mailto:[email protected]] On Behalf Of John Woodgate Sent: Monday, April 13, 2009 1:09 PM To: [email protected] Subject: Re: Equipment in series, now time to time. "From Time to Time" In message <[email protected]>, dated Mon, 13 Apr 2009, "Kunde, Brian" <[email protected]> writes: >You would think with all the Test Lab representatives who sit on >Standards Writing Committees there would be an audit standard or at >least some mention of it is every test standard. It's not up to test labs. Remember that every test lab expert who proposes a tighter requirement loses his company an uncertain number of clients. It's up to spectrum management authorities to propose unpopular measures, and in standards committees they are always challenged to justify their proposals. Some who try to impose national measures in Europe risk censure by the Community administration (Commission and Parliament). >The 80/80 rule in Emissions standards is almost never followed to the >letter or to its intent. 80/80 is really intended for large volume products. Just how large is a matter for debate; with smaller volumes, less deviation from the average can be expected, which can balance the statistical uncertainty due to the smaller population. >Most companies get their Golden Unit to pass and production units are >never verified. Very sad. It isn't sad if there are no bad consequences. Every time a re-test shows a pass, time and money has been spent for no useful outcome, and potentially an increase in product price or a reduction in margin. Please don't become an 'EMC crusader' - favouring continually tightening limits and rigid enforcement regardless of cost. Complaint-drive surveillance is the most sensible regime for EMC (but not for safety). There are enough official (some anonymous) bodies monitoring the electromagnetic spectrum these days in developed countries to catch any significant problem at an early stage. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Things can always get better. But that's not the only option. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - 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://www.ieeecommunities.org/emc-pstc 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]> LECO Corporation Notice: This communication may contain confidential information intended for the named recipient(s) only. If you received this by mistake, please destroy it and notify us of the error. Thank you. - 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://www.ieeecommunities.org/emc-pstc 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]>
