Hi Chas, This is how I interpret the standard. Somewhere I recall if painted surfaces can be penetrated by the point, then Contact also applies.
Cheers, Derek. Grasso, Charles wrote: > The ESD standard is perfectly clear (at least to me) - The product > is tested using contact discharge for conductive surfaces > AND air discharge on insulating surfaces. > > I don't perceive an interpretation issue. > > If your product is a object constructed entirely > of a conductive material - contact discharge only applies. Similarly if > the product is an object constructed entirely of an insulator then only > air discharge applies. If your product has combinations of both - then > both types of discharges apply. > > Is this reasoning flawed?? > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of John > Woodgate > Sent: Friday, May 22, 2009 7:50 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. > > > - 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]>
