Don't know about a reasonable match to field events, but if you look it as, "What's likely ?" we're all charged to a few kV every day -- some more than others --- especially if you're in Calgary during January! Most people can't feel a discharge until you get to a couple of kV; most everyone feels 5kV, and EVERYONE remembers 15kV. Seems likely to me that testing for more than a few kV is a good thing (4 - 6kV sounds good), but testing at 15kV might be overkill -- unless of course, you're in the Calgary lawyers office with a shag carpet in January.... The whole premise of the European Norms (the driver for IEC/EN 61000-4-2 becoming the world-wide standard for ESD testing at the system level) is to get everyone on a level playing field --- establish minimum immunity and emissions levels for all products to environmental effects (EMC). Keep in mind, EN61000-4-2 is NOT the standard for establishing minimum test levels -- it is the document that tells you how to do the test and provides some recommended levels, but the enforcement document is the product or product family standard. Not all, but many of these standards require testing at 4kV contact mode and 8kV air discharge. IEC/EN 61000-4-2 is certainly the way you should do a test if it's be considered credible; the level's another issue.... Michael Hopkins - (K1VLB for those who know what it means)
Thermo Fisher Scientific One Lowell Research Center Lowell, MA 01852 Tel: +1 978 275 0800 ext. 334 Fax: +1 978 275 0850 mobile: +1 603 765 3736 [email protected] _____ From: [email protected] [mailto:[email protected]] On Behalf Of Cortland Richmond Sent: Monday, December 17, 2007 7:35 AM To: [email protected] Subject: Re: EN61000 - 4 - 2 - How far it is matching with field results? I'll add to John Woodgate's remarks a thought of my own: Failures might simply be thrown away by the user, while the seller claims "Not a single field return world wide!" As some wit once wrote, "The absence of evidence is not evidence of absence." Then too, many manufacturers consider a fine merely the cost doing business, and will leave out components whose only purpose is to avert an unlikely failure. A lot of computer power supplies have jumpers where filters could go! Wilful ignorance raises profits. Cortland Richmond KA5S -----Original Message----- From: Bharathkumar Raju Sent: Dec 16, 2007 10:03 PM To: [email protected] Subject: EN61000 - 4 - 2 - How far it is matching with field results? Dear Memebrs, I feel EN61000 - 4 - 2 is an over kill for assessing the ESD immunity level of a device. An USB device with a CCD type sensor is repeatedly failing in the lab testing conducted as per the standard and as per sensor manufacturer's recomendations. On the other hand the sensor manufacturer claims that millions of sensors are deployed in the field for more than a year and absolutely no field returns on ESD account. The lab results are not at all matching with field results calimed by the sensor manufacturer. As a product certification engineer, I am confused whether to give the go ahead to my company for the mass production. I look for the members advise a. Do you see a reasonable match between the EN 61000 - 4 - 2 lab test results and field results. b. Is there any other standard that you feel better than EN 61000 - 4 - 2. Wishing you all a Happy Christmas & Prosperous New Year 2008 Bharath - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
