Derek, ANSI C63.16:1991 : "Guide for ESD test methodologies and criteria for electronic equipment", has/had a requirement for barometric pressure and ESD.
I don't have a current version of the standard and couldn't tell you if the statement is still there; or for that matter, if the standard is still maintained. Section 5.2.1 "Air Breakdown Voltage Test Value Air breakdown at a fixed distance between arcing electrodes is approximately proportional to the atmospheric pressure and inversely proportional to absolute (degrees-Kelvin) temperature. Therefore when testing EUT's for air breakdown (external or internal with either test method), the ESD voltage level shall be changed to reflect the test equipment specification and the environmental conditions. Typically, air breakdown at sea level will be about 40% higher than at 3000m. Failure to change the test voltage for pressure will create site to site immunity variations in the EUT air breakdown values." Years ago, when ESD testing to 801-2: 1991 we would increase the air discharge test voltage/value between 500V @ 8KV and 100V @ 2KV, based on our labs elevation. While that statement was not in 801-2: 1991, it was a recommendation >from a member of the ANSI ESD committee who was an employee at the time when we were trying to explain site to site variations in ESD results. Regards, David Spencer EMC Engineer Xerox Corp From: [email protected] [mailto:[email protected]] On Behalf Of Derek Walton Sent: Monday, March 31, 2008 8:14 PM To: Pettit, Ghery Cc: [email protected]; Garnier, David S (GE Healthcare); [email protected] Subject: Re: Looking for Barometric pressure meter Hi Ghery, I'm curious as to which EMI test requires pressure, and has limits set for it? Cheers, Derek Walton L F Research Pettit, Ghery wrote: > > The information provided by the FAA and weather guessers is pressure > corrected to sea level. It is not the actual pressure. I can get an > altimeter setting in Denver (mile high) or Olympia (206 ft MSL) and it > will be in the same range, even though the actual pressure in Denver > is about 5 inches of mercury lower. This is one of my favorite > questions when auditing a lab when they have a barometer on the wall - > is that absolute pressure, or corrected to sea level? And I usually > get blank looks. And you want to report absolute pressure. > > Ghery Pettit > > PP-ASEL > > > > *From:* [email protected] [mailto:[email protected]] *On Behalf Of > *Cortland Richmond > *Sent:* Saturday, March 29, 2008 2:44 PM > *To:* Garnier, David S (GE Healthcare); [email protected] > *Subject:* RE: Looking for Barometric pressure meter > > Why not get the air pressure from the nearest FAA control tower by > radio? Critesfield Airport in Waukesha broadcasts airfield information > that includes updated barometric pressure > > http://www.critesfield.com/facilities/ > > Cortland > > KAS/6 > > ----- Original Message ----- > > *From:* Garnier, David S (GE Healthcare) > <mailto:[email protected]> > > *To: *[email protected] <mailto:[email protected]> > > *Sent:* 3/28/2008 10:25:25 AM > > *Subject:* Looking for Barometric pressure meter > > Hello, > > I am looking for advice or suggestions for the purchase of a > Barometric pressure meter for our EMC lab... > > - ---------------------------------------------------------------- > 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 > - 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
