IF there is an unseen "or" in the list of discharge types, then why does the Standard not give any guidance on which method to choose in cases where the EUT has both plastic and metallic outer surfaces?
Since it does not, I cannot see any other course of action on mixed materials products other than to do both tests as appropriate, based on the clarifications in -4-2 for the two surface types. Bryce Stammerjohan | Research & Development Engineer Thoratec Corporation | 6035 Stoneridge Drive, Pleasanton, CA 94588 From: John Woodgate [mailto:[email protected]] Sent: Friday, May 22, 2009 6:50 AM To: [email protected] Subject: Re: [PSES] ESD testing In message <[email protected]>, dated Fri, 22 May 2009, Kate Savo <[email protected]> writes: >Safety/EMC Standards frequently omit the "and" in a list of items such >as you excerpted here from 61000-4-2 - they only put an "or" in where >they truly mean it to be interpreted as such. > >The "and" is implied and Contact ESD must be done on all conductive >surfaces, and Air ESD on all insulating surfaces. If your product has >both surface types, you should not omit either test scenario. Your >local EMC/ESD lab should confirm this. I do not support that interpretation. If the list just said: - air discharge; - contact discharge to conductive surfaces, conducting planes and insulating surfaces. then 'and' might be inferred. But in fact, the inclusion of further words, defining the surfaces to which the two types of discharge shall be applied, excludes such an inference: a) contact discharge to the conductive surfaces and coupling planes; b) air discharge at insulating surfaces. -- 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]> - 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]>
