If the requirement is for documentation only, whats the point of doing it? Now, if it were required to adjust levels based on pressure, then it would be a worth while exercise.
In reality, I doubt anyone would ever notice the difference: after all ESD is Sooooo repeatable :-) Cheers, Derek Walton Spencer, David H wrote: > > > If the ANSI ESD standard is correct, in that "Air breakdown at a fixed > distance > between arcing electrodes is approximately proportional to the > atmospheric pressure..... " and "Typically, air breakdown at sea > level will be about 40% higher than at 3000m." > > By removing it, aren't you introducing a additional undocumented source > of inconsistency? > > Dave Spencer > > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of Derek > Walton > Sent: Tuesday, April 01, 2008 12:24 PM > To: Pettit, Ghery > Cc: [email protected]; [email protected] > Subject: Re: Looking for Barometric pressure meter > > More interestingly, since it seems of little significance, why not > remove the requirement altogether. One less source of inconsistency... > > Derek Walton > > Pettit, Ghery wrote: > >> Which brings up the question - if the tests may be performed at any >> pressure for which the EUT is rated, why specify a range in the first >> place? >> >> And, to my knowledge, this isn't under discussion for any of the >> documents under SC77B at this time. SC77B "owns" the 61000-4-x >> documents we're discussing here. Important enough for me to bring up >> to the US national committee? >> >> Ghery Pettit >> >> >> > ------------------------------------------------------------------------ > >> *From:* [email protected] [mailto:[email protected]] *On Behalf Of >> *[email protected] >> *Sent:* Tuesday, April 01, 2008 9:08 AM >> *To:* [email protected] >> *Subject:* RE: Looking for Barometric pressure meter >> >> >> In IEC61000-4-5:1995 (Line Surge Immunity), clause 8.1.1 specified a >> range of barometric pressure for testing. However, IEC61000-4-5:1995 >> Amd. 1 changes that to say: >> "... the climatic conditions in the laboratory shall be within any >> limits specified for the operation of the EUT and the test equipment >> by their respective manufacturers." >> In other words, you can do the test at any barometric pressure, so >> long as the equipment is rated for it. >> >> It wouldn't surprise me if that type of change is (or will be) >> incorporated into other IEC test documents. >> >> Pat Lawler >> EMC Engineer >> SL Power Electronics Corp. >> >> [email protected] wrote on 04/01/2008 08:34:51 AM: >> >>> In quickly checking the 61000-4-x series that are called out in >>> > CISPR > >>> 24, IEC 61000-4-2 (ESD) is the only one. Section 8.1.1 calls out the >>> acceptable climatic conditions for performing the tests, and the >>> atmospheric pressure must be between 86 kPa and 106 kPa. That's a >>> > range > >>> of 25.4 inches of Hg to 31.3 inches of Hg. As standard atmosphere at >>> sea level is 29.92 inches of Hg at 59 degrees F, and pressure drops >>> about 1 inch per 1000 feet of altitude gain, you can see that you >>> > hit > >>> the minimum pressure on a standard day at 4520 feet. Denver is at >>> > 5280 > >>> feet (one of the steps on city hall). Not sure how you can "legally" >>> perform ESD testing in EMC labs in most of Colorado. :-) >>> >>> Ghery >>> >>> -----Original Message----- >>> From: Derek Walton [mailto:[email protected]] >>> Sent: Monday, March 31, 2008 5:14 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 >> >> - ---------------------------------------------------------------- >> 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
