Re: [PSES] thoughts on ESD test lab problems
I really hope not. See my story 'How to lose half a million dollars': /April 2 2014 From: Compliance (JH) To: MJ54 Team Leader (BB) Subject: MJ54 tests Not good news. Model for testing (MFT) failed several EMC tests, and there are safety issues as well. Details in a following message. Can we discuss? May 30 2014 From: BB To: JH Subject: MJ54 tests cc: Manager, R&D I regret the delay in our discussion due to our incompatible schedules. Your proposals for MJ54 are simply unacceptable; a $5 on-cost and a redesign of the PC board and enclosure to accommodate the larger EMI filter compromise both the costing and the time-scale already submitted to Marketing and approved. In addition, the bandwidth reserve of stage 1 has been reduced to such an extent that conformity with specification cannot be assured in production. July 31 2014 From: Manager, Compliance To: Manager, R&D Subject: MJ54 After investigation, I confirm that the measures requested by JH are fully justified and essential. I also consider it most regrettable that both JH and BB are under suspension as a result of an altercation admittedly instigated by BB. September 29 2014 From: VP Marketing To: VP R&D cc: President Subject: MJ54 The increased cost and revised time-scale that you have submitted make the product unviable. In addition, our original request to include BGQQ compatibility if possible, which you declined to fulfil, is no longer an option. Acme and two other competitors now have products with full BGQQ compatibility at prices 10% lower than your original costing indicated. / On 2023-08-13 16:47, Ralph McDiarmid wrote: I wonder why industry is spending so much on EMC compliance. Is it because the development teams are leaving this work to the final phase of the design, where changes are expensive and schedules slip ? - 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 All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe) List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: msherma...@comcast.net Rick Linford at: linf...@ieee.org For policy questions, send mail to: Jim Bacher: _ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1
Re: [PSES] thoughts on ESD test lab problems
I wonder why industry is spending so much on EMC compliance. Is it because the development teams are leaving this work to the final phase of the design, where changes are expensive and schedules slip ? Ralph From: doug emcesd.com Sent: Saturday, August 12, 2023 8:57 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] thoughts on ESD test lab problems Thanks everyone for your thoughts. But in the case of ESD testing, IEC 61000-4-2 is not a very good standard. We knew this in 1996 where work done by myself and others showed that the waveform needs to have a di/dt spec to rule out the uncontrolled high frequency ringing many simulators generate that bear no connection to reality. This should be a reasonable simple design to do as one simulator already has no high frequency ringing on its current waveform. In addition, we now know these same simulators have uncontrolled radiation as well that does not reflect what equipment is subjected to in the field. All the work on the waveform was done about 30 years ago and should be in the IEC records. All this causes companies to spend hundreds of millions of dollars (my estimate from familiarity with my client’s designs) per year in delayed product introductions, and to a small extent engineering costs. The costs to redesign simulators would be a tiny fraction of what the current costs to industry are in only one year. Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: d...@dsmith.org <mailto:d...@dsmith.org> Website: http://dsmith.org _ From: Brent DeWitt mailto:bdew...@ix.netcom.com> > Sent: Saturday, August 12, 2023 5:05:40 PM To: EMC-PSTC@LISTSERV.IEEE.ORG <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> mailto:EMC-PSTC@LISTSERV.IEEE.ORG> > Subject: Re: [PSES] thoughts on ESD test lab problems I suspect that folks who have been directly involved with air-discharge ESD can appreciate it's inherent, operator influenced, uncertainly. Having run both internal and third party EMC test labs, I recognize that few things are done "perfectly" (whatever "perfect" is), but I've always considered it my responsibility to catch the errors and correct them before they influence my customers outcome. The larger the lab, the more likely it is that the experience of the tester will vary. I am not saying that the customer show bear the brunt of that, the lab should have test review processes in place to mitigate it. Had to pitch in. Brent DeWitt On 8/12/2023 1:47 PM, John Mcbain wrote: The basic question is, "How good is good enough?" Risk standards for product safety address that question to some extent, but it applies to every lab measurement, whether the applicable standards (or regulations) consider it or not. Best regards, John McBain On Sat, Aug 12, 2023 at 2:26 AM John Woodgate mailto:j...@woodjohn.uk> > wrote: But crossing t's and dotting i's is exactly what is required by competence standards, including the several ISO 170XX series. Furthermore, standards specify performance of test equipment, if possible, and only if that is not possible, they specify design. If that is not possible, they specify construction, and indeed many CISPR and other standards specify test set-ups with elaborate drawings. EMC testing is DIFFICULT. It does involve extensive experience and it is costly. Management systems are/should be in place to catch errors. Daily and weekly verifications are required. In many cases, running tests on a known sample are OK, but that's dodgy for ESD, because repeated testing WILL cause damage. On 2023-08-12 03:25, Ken Javor wrote: No way am I jumping in the middle of this debate, but it is extremely useful in another way. A few observations: ESD is by its very nature a chaotic event (air discharge more so than contact). It is not entirely surprising that someone who has spent decades working on something would find examples of non-idealities in the work of technicians doing rote work following canned test procedures. A test facility isn’t going to make a profit employing a septuagenarian devoted to crossing every “t” and dotting every “i.” (Written by someone pushing that age bracket pretty hard). IFF (if and only if) Mr. Smith’s observations are correct, that is an indictment of the test requirement/method. That is, it is the responsibility of the standards committees to write these such that they can be adequately performed by the average test facility and personnel. If it takes someone with five decades of experience, and they must spend an inordinate amount of time ($$$) to get it right, then the standard is a failure. -- Ken Javor (256) 650-5261 From: "doug emcesd.com <https://urldefense.proofpoint.com/v2/url?u=http-3A__emcesd.com&d=DwMDaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_Cdpg
Re: [PSES] thoughts on ESD test lab problems
Thanks everyone for your thoughts. But in the case of ESD testing, IEC 61000-4-2 is not a very good standard. We knew this in 1996 where work done by myself and others showed that the waveform needs to have a di/dt spec to rule out the uncontrolled high frequency ringing many simulators generate that bear no connection to reality. This should be a reasonable simple design to do as one simulator already has no high frequency ringing on its current waveform. In addition, we now know these same simulators have uncontrolled radiation as well that does not reflect what equipment is subjected to in the field. All the work on the waveform was done about 30 years ago and should be in the IEC records. All this causes companies to spend hundreds of millions of dollars (my estimate from familiarity with my client’s designs) per year in delayed product introductions, and to a small extent engineering costs. The costs to redesign simulators would be a tiny fraction of what the current costs to industry are in only one year. Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: d...@dsmith.org Website: http://dsmith.org From: Brent DeWitt Sent: Saturday, August 12, 2023 5:05:40 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] thoughts on ESD test lab problems I suspect that folks who have been directly involved with air-discharge ESD can appreciate it's inherent, operator influenced, uncertainly. Having run both internal and third party EMC test labs, I recognize that few things are done "perfectly" (whatever "perfect" is), but I've always considered it my responsibility to catch the errors and correct them before they influence my customers outcome. The larger the lab, the more likely it is that the experience of the tester will vary. I am not saying that the customer show bear the brunt of that, the lab should have test review processes in place to mitigate it. Had to pitch in. Brent DeWitt On 8/12/2023 1:47 PM, John Mcbain wrote: The basic question is, "How good is good enough?" Risk standards for product safety address that question to some extent, but it applies to every lab measurement, whether the applicable standards (or regulations) consider it or not. Best regards, John McBain On Sat, Aug 12, 2023 at 2:26 AM John Woodgate mailto:j...@woodjohn.uk>> wrote: But crossing t's and dotting i's is exactly what is required by competence standards, including the several ISO 170XX series. Furthermore, standards specify performance of test equipment, if possible, and only if that is not possible, they specify design. If that is not possible, they specify construction, and indeed many CISPR and other standards specify test set-ups with elaborate drawings. EMC testing is DIFFICULT. It does involve extensive experience and it is costly. Management systems are/should be in place to catch errors. Daily and weekly verifications are required. In many cases, running tests on a known sample are OK, but that's dodgy for ESD, because repeated testing WILL cause damage. On 2023-08-12 03:25, Ken Javor wrote: No way am I jumping in the middle of this debate, but it is extremely useful in another way. A few observations: ESD is by its very nature a chaotic event (air discharge more so than contact). It is not entirely surprising that someone who has spent decades working on something would find examples of non-idealities in the work of technicians doing rote work following canned test procedures. A test facility isn’t going to make a profit employing a septuagenarian devoted to crossing every “t” and dotting every “i.” (Written by someone pushing that age bracket pretty hard). IFF (if and only if) Mr. Smith’s observations are correct, that is an indictment of the test requirement/method. That is, it is the responsibility of the standards committees to write these such that they can be adequately performed by the average test facility and personnel. If it takes someone with five decades of experience, and they must spend an inordinate amount of time ($$$) to get it right, then the standard is a failure. -- Ken Javor (256) 650-5261 From: "doug emcesd.com<https://urldefense.proofpoint.com/v2/url?u=http-3A__emcesd.com&d=DwMDaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=c9NR2mGfldry-2pM9Bbuww&m=2PwUVOf-nkk5PGnCGiZ_awAOCLYGgF6VrmmUR0MyZYVG8A4TDFmh_VavNrLO9d-D&s=6y86ulvOYE9KMhGkDV_GoB-siQVeeaqGTdX8FXX3cRg&e=>" <mailto:d...@emcesd.com> Reply-To: "doug emcesd.com<https://urldefense.proofpoint.com/v2/url?u=http-3A__emcesd.com&d=DwMDaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=c9NR2mGfldry-2pM9Bbuww&m=2PwUVOf-nkk5PGnCGiZ_awAOCLYGgF6VrmmUR0MyZYVG8A4TDFmh_VavNrLO9d-D&s=6y86ulvOYE9KMhGkDV_GoB-siQVeeaqGTdX8FXX3cRg&e=>" <mailto:d...@emcesd.co
Re: [PSES] thoughts on ESD test lab problems
I suspect that folks who have been directly involved with air-discharge
ESD can appreciate it's inherent, operator influenced, uncertainly.
Having run both internal and third party EMC test labs, I recognize that
few things are done "perfectly" (whatever "perfect" is), but I've always
considered it my responsibility to catch the errors and correct them
before they influence my customers outcome.
The larger the lab, the more likely it is that the experience of the
tester will vary. I am not saying that the customer show bear the brunt
of that, the lab should have test review processes in place to mitigate it.
Had to pitch in.
Brent DeWitt
On 8/12/2023 1:47 PM, John Mcbain wrote:
The basic question is, "How good is good enough?"
Risk standards for product safety address that question to some
extent, but it applies to every lab measurement, whether the
applicable standards (or regulations) consider it or not.
Best regards,
John McBain
On Sat, Aug 12, 2023 at 2:26 AM John Woodgate wrote:
But crossing t's and dotting i's is exactly what is required by
competence standards, including the several ISO 170XX series.
Furthermore, standards specify performance of test equipment, if
possible, and only if that is not possible, they specify design.
If that is not possible, they specify construction, and indeed
many CISPR and other standards specify test set-ups with elaborate
drawings.
EMC testing is DIFFICULT. It does involve extensive experience and
it is costly. Management systems are/should be in place to catch
errors. Daily and weekly verifications are required. In many
cases, running tests on a known sample are OK, but that's dodgy
for ESD, because repeated testing WILL cause damage.
On 2023-08-12 03:25, Ken Javor wrote:
No way am I jumping in the middle of this debate, but it is
extremely useful in another way.
A few observations:
ESD is by its very nature a chaotic event (air discharge more so
than contact).
It is not entirely surprising that someone who has spent decades
working on something would find examples of non-idealities in the
work of technicians doing rote work following canned test
procedures. A test facility isn’t going to make a profit
employing a septuagenarian devoted to crossing every “t” and
dotting every “i.” (Written by someone pushing that age bracket
pretty hard).
IFF (if and only if) Mr. Smith’s observations are correct, that
is an indictment of the test requirement/method. That is, it is
the responsibility of the standards committees to write these
such that they can be adequately performed by the average test
facility and personnel. If it takes someone with five decades of
experience, and they must spend an inordinate amount of time
($$$) to get it right, then the standard is a failure.
--
Ken Javor
(256) 650-5261
*From: *"doug emcesd.com <http://emcesd.com>"
<mailto:d...@emcesd.com>
*Reply-To: *"doug emcesd.com <http://emcesd.com>"
<mailto:d...@emcesd.com>
*Date: *Friday, August 11, 2023 at 11:26 AM
*To: *
<mailto:EMC-PSTC@LISTSERV.IEEE.ORG>
*Subject: *Re: [PSES] thoughts on ESD test lab problems
I didn’t say most labs are bad. Errors do happen and for me
almost every lab I have used has made a mistake. These errors are
rare but do happen and the effect of a single error can be very
costly.
One lab made an especially bad mistake for a small company that
engaged me that cost the company a lot of money, has since
improved their game by instituting quality procedures they should
have had anyway. The lab gave the company passing data but in
fact the plot looked like the technician forgot to plug the
antenna in, noise level of the instrumentation!
Based on that, the company signed a contract for price and
delivery for a million units of their product. The ultimate fix
needed was a different core design of an inductor that cost them
US $0.30. $300k is a lot of money for a small company.
I can give many more examples. Usually the problem causes a
product to fail when it actually should have passed. I have many
examples that happened to me over the last 40 years in both
private and commercial labs.
The errors are still rare, but do happen. Over enough testing a
person, like myself, will encounter an error with any given lab.
Of the errors I have encountered, three were the result of the
staff in the lab not being competent (over a span of 40 years),
the rest were just simple mistakes, maybe another dozen or so.
Again, this was over decades, so rare, but many millions of
dollars were at stake in each case.
In two cases, the lab personnel became a bit belligerent
Re: [PSES] thoughts on ESD test lab problems
The basic question is, "How good is good enough?" Risk standards for product safety address that question to some extent, but it applies to every lab measurement, whether the applicable standards (or regulations) consider it or not. Best regards, John McBain On Sat, Aug 12, 2023 at 2:26 AM John Woodgate wrote: > But crossing t's and dotting i's is exactly what is required by competence > standards, including the several ISO 170XX series. Furthermore, standards > specify performance of test equipment, if possible, and only if that is not > possible, they specify design. If that is not possible, they specify > construction, and indeed many CISPR and other standards specify test > set-ups with elaborate drawings. > > EMC testing is DIFFICULT. It does involve extensive experience and it is > costly. Management systems are/should be in place to catch errors. Daily > and weekly verifications are required. In many cases, running tests on a > known sample are OK, but that's dodgy for ESD, because repeated testing > WILL cause damage. > On 2023-08-12 03:25, Ken Javor wrote: > > No way am I jumping in the middle of this debate, but it is extremely > useful in another way. > > > > A few observations: > > > > ESD is by its very nature a chaotic event (air discharge more so than > contact). > > > > It is not entirely surprising that someone who has spent decades working > on something would find examples of non-idealities in the work of > technicians doing rote work following canned test procedures. A test > facility isn’t going to make a profit employing a septuagenarian devoted to > crossing every “t” and dotting every “i.” (Written by someone pushing that > age bracket pretty hard). > > > > IFF (if and only if) Mr. Smith’s observations are correct, that is an > indictment of the test requirement/method. That is, it is the > responsibility of the standards committees to write these such that they > can be adequately performed by the average test facility and personnel. If > it takes someone with five decades of experience, and they must spend an > inordinate amount of time ($$$) to get it right, then the standard is a > failure. > > > > -- > > Ken Javor > > (256) 650-5261 > > > > *From: *"doug emcesd.com" > *Reply-To: *"doug emcesd.com" > *Date: *Friday, August 11, 2023 at 11:26 AM > *To: * > *Subject: *Re: [PSES] thoughts on ESD test lab problems > > > > I didn’t say most labs are bad. Errors do happen and for me almost every > lab I have used has made a mistake. These errors are rare but do happen and > the effect of a single error can be very costly. > > > > One lab made an especially bad mistake for a small company that engaged me > that cost the company a lot of money, has since improved their game by > instituting quality procedures they should have had anyway. The lab gave > the company passing data but in fact the plot looked like the technician > forgot to plug the antenna in, noise level of the instrumentation! > > > > Based on that, the company signed a contract for price and delivery for a > million units of their product. The ultimate fix needed was a different > core design of an inductor that cost them US $0.30. $300k is a lot of money > for a small company. > > > > I can give many more examples. Usually the problem causes a product to > fail when it actually should have passed. I have many examples that > happened to me over the last 40 years in both private and commercial labs. > > > > The errors are still rare, but do happen. Over enough testing a person, > like myself, will encounter an error with any given lab. > > > > Of the errors I have encountered, three were the result of the staff in > the lab not being competent (over a span of 40 years), the rest were just > simple mistakes, maybe another dozen or so. Again, this was over decades, > so rare, but many millions of dollars were at stake in each case. > > > > In two cases, the lab personnel became a bit belligerent when I gently > suggested they performed the test incorrectly. In both cases, the labs > relented and retested after we examined the test standard and they realized > they were testing incorrectly. > > > > A lab client needs to keep an eye out to make sure such an error does not > happen to them. > > > > On the other hand, I have seen a lot of great labs. One, in Silicon > Valley, I consider to be the best in the industry! But they did make one > mistake on a test for me years ago, minimal impact at the time and it can't > happen again. > > > > Doug Smith > > Sent from my iPhone > > IPhone: 408-858
Re: [PSES] thoughts on ESD test lab problems
But crossing t's and dotting i's is exactly what is required by competence standards, including the several ISO 170XX series. Furthermore, standards specify performance of test equipment, if possible, and only if that is not possible, they specify design. If that is not possible, they specify construction, and indeed many CISPR and other standards specify test set-ups with elaborate drawings. EMC testing is DIFFICULT. It does involve extensive experience and it is costly. Management systems are/should be in place to catch errors. Daily and weekly verifications are required. In many cases, running tests on a known sample are OK, but that's dodgy for ESD, because repeated testing WILL cause damage. On 2023-08-12 03:25, Ken Javor wrote: No way am I jumping in the middle of this debate, but it is extremely useful in another way. A few observations: ESD is by its very nature a chaotic event (air discharge more so than contact). It is not entirely surprising that someone who has spent decades working on something would find examples of non-idealities in the work of technicians doing rote work following canned test procedures. A test facility isn’t going to make a profit employing a septuagenarian devoted to crossing every “t” and dotting every “i.” (Written by someone pushing that age bracket pretty hard). IFF (if and only if) Mr. Smith’s observations are correct, that is an indictment of the test requirement/method. That is, it is the responsibility of the standards committees to write these such that they can be adequately performed by the average test facility and personnel. If it takes someone with five decades of experience, and they must spend an inordinate amount of time ($$$) to get it right, then the standard is a failure. -- Ken Javor (256) 650-5261 *From: *"doug emcesd.com" *Reply-To: *"doug emcesd.com" *Date: *Friday, August 11, 2023 at 11:26 AM *To: * *Subject: *Re: [PSES] thoughts on ESD test lab problems I didn’t say most labs are bad. Errors do happen and for me almost every lab I have used has made a mistake. These errors are rare but do happen and the effect of a single error can be very costly. One lab made an especially bad mistake for a small company that engaged me that cost the company a lot of money, has since improved their game by instituting quality procedures they should have had anyway. The lab gave the company passing data but in fact the plot looked like the technician forgot to plug the antenna in, noise level of the instrumentation! Based on that, the company signed a contract for price and delivery for a million units of their product. The ultimate fix needed was a different core design of an inductor that cost them US $0.30. $300k is a lot of money for a small company. I can give many more examples. Usually the problem causes a product to fail when it actually should have passed. I have many examples that happened to me over the last 40 years in both private and commercial labs. The errors are still rare, but do happen. Over enough testing a person, like myself, will encounter an error with any given lab. Of the errors I have encountered, three were the result of the staff in the lab not being competent (over a span of 40 years), the rest were just simple mistakes, maybe another dozen or so. Again, this was over decades, so rare, but many millions of dollars were at stake in each case. In two cases, the lab personnel became a bit belligerent when I gently suggested they performed the test incorrectly. In both cases, the labs relented and retested after we examined the test standard and they realized they were testing incorrectly. A lab client needs to keep an eye out to make sure such an error does not happen to them. On the other hand, I have seen a lot of great labs. One, in Silicon Valley, I consider to be the best in the industry! But they did make one mistake on a test for me years ago, minimal impact at the time and it can't happen again. Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: d...@dsmith.org Website: http://dsmith.org *From:* John Woodgate *Sent:* Friday, August 11, 2023 07:02 *To:* EMC-PSTC@LISTSERV.IEEE.ORG *Subject:* Re: [PSES] thoughts on ESD test lab problems That's right. It is good to call attention to problems that may well be deeply hidden or not recognized as a possibility, but it is necessary to concentrate on the facts and leave out peripheral matters that don't help to deal with the issue. On 2023-08-11 14:28, Larry K. Stillings wrote: You could certainly word this in a different way that doesn’t generalize how “most” test labs are bad and/or incompetent. How about in the future you find a different way to word things. -
Re: [PSES] thoughts on ESD test lab problems
No way am I jumping in the middle of this debate, but it is extremely useful in another way. A few observations: ESD is by its very nature a chaotic event (air discharge more so than contact). It is not entirely surprising that someone who has spent decades working on something would find examples of non-idealities in the work of technicians doing rote work following canned test procedures. A test facility isn’t going to make a profit employing a septuagenarian devoted to crossing every “t” and dotting every “i.” (Written by someone pushing that age bracket pretty hard). IFF (if and only if) Mr. Smith’s observations are correct, that is an indictment of the test requirement/method. That is, it is the responsibility of the standards committees to write these such that they can be adequately performed by the average test facility and personnel. If it takes someone with five decades of experience, and they must spend an inordinate amount of time ($$$) to get it right, then the standard is a failure. -- Ken Javor (256) 650-5261 From: "doug emcesd.com" Reply-To: "doug emcesd.com" Date: Friday, August 11, 2023 at 11:26 AM To: Subject: Re: [PSES] thoughts on ESD test lab problems I didn’t say most labs are bad. Errors do happen and for me almost every lab I have used has made a mistake. These errors are rare but do happen and the effect of a single error can be very costly. One lab made an especially bad mistake for a small company that engaged me that cost the company a lot of money, has since improved their game by instituting quality procedures they should have had anyway. The lab gave the company passing data but in fact the plot looked like the technician forgot to plug the antenna in, noise level of the instrumentation! Based on that, the company signed a contract for price and delivery for a million units of their product. The ultimate fix needed was a different core design of an inductor that cost them US $0.30. $300k is a lot of money for a small company. I can give many more examples. Usually the problem causes a product to fail when it actually should have passed. I have many examples that happened to me over the last 40 years in both private and commercial labs. The errors are still rare, but do happen. Over enough testing a person, like myself, will encounter an error with any given lab. Of the errors I have encountered, three were the result of the staff in the lab not being competent (over a span of 40 years), the rest were just simple mistakes, maybe another dozen or so. Again, this was over decades, so rare, but many millions of dollars were at stake in each case. In two cases, the lab personnel became a bit belligerent when I gently suggested they performed the test incorrectly. In both cases, the labs relented and retested after we examined the test standard and they realized they were testing incorrectly. A lab client needs to keep an eye out to make sure such an error does not happen to them. On the other hand, I have seen a lot of great labs. One, in Silicon Valley, I consider to be the best in the industry! But they did make one mistake on a test for me years ago, minimal impact at the time and it can't happen again. Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: d...@dsmith.org Website: http://dsmith.org From: John Woodgate Sent: Friday, August 11, 2023 07:02 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] thoughts on ESD test lab problems That's right. It is good to call attention to problems that may well be deeply hidden or not recognized as a possibility, but it is necessary to concentrate on the facts and leave out peripheral matters that don't help to deal with the issue. On 2023-08-11 14:28, Larry K. Stillings wrote: You could certainly word this in a different way that doesn’t generalize how “most” test labs are bad and/or incompetent. How about in the future you find a different way to word things. 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 All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe) List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: msherma...@comcast.net Rick Linford at: linf...@ieee.org For policy questions, send mail to: Jim Bacher at: j.bac...@ieee.org To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1 This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the
Re: [PSES] thoughts on ESD test lab problems
I didn’t say most labs are bad. Errors do happen and for me almost every lab I have used has made a mistake. These errors are rare but do happen and the effect of a single error can be very costly. One lab made an especially bad mistake for a small company that engaged me that cost the company a lot of money, has since improved their game by instituting quality procedures they should have had anyway. The lab gave the company passing data but in fact the plot looked like the technician forgot to plug the antenna in, noise level of the instrumentation! Based on that, the company signed a contract for price and delivery for a million units of their product. The ultimate fix needed was a different core design of an inductor that cost them US $0.30. $300k is a lot of money for a small company. I can give many more examples. Usually the problem causes a product to fail when it actually should have passed. I have many examples that happened to me over the last 40 years in both private and commercial labs. The errors are still rare, but do happen. Over enough testing a person, like myself, will encounter an error with any given lab. Of the errors I have encountered, three were the result of the staff in the lab not being competent (over a span of 40 years), the rest were just simple mistakes, maybe another dozen or so. Again, this was over decades, so rare, but many millions of dollars were at stake in each case. In two cases, the lab personnel became a bit belligerent when I gently suggested they performed the test incorrectly. In both cases, the labs relented and retested after we examined the test standard and they realized they were testing incorrectly. A lab client needs to keep an eye out to make sure such an error does not happen to them. On the other hand, I have seen a lot of great labs. One, in Silicon Valley, I consider to be the best in the industry! But they did make one mistake on a test for me years ago, minimal impact at the time and it can't happen again. Doug Smith Sent from my iPhone IPhone: 408-858-4528 Office: 702-570-6108 Email: d...@dsmith.org Website: http://dsmith.org From: John Woodgate Sent: Friday, August 11, 2023 07:02 To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] thoughts on ESD test lab problems That's right. It is good to call attention to problems that may well be deeply hidden or not recognized as a possibility, but it is necessary to concentrate on the facts and leave out peripheral matters that don't help to deal with the issue. On 2023-08-11 14:28, Larry K. Stillings wrote: You could certainly word this in a different way that doesn’t generalize how “most” test labs are bad and/or incompetent. How about in the future you find a different way to word things. 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 All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/<https://urldefense.proofpoint.com/v2/url?u=https-3A__www.mail-2Darchive.com_emc-2Dpstc-40listserv.ieee.org_&d=DwMDaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=c9NR2mGfldry-2pM9Bbuww&m=AQbLI6yYUde_Q83E8xm-giFuu8VErE5y8fOfergBM5iZxYk2-pO-cenWPMbLLBpM&s=m4yUzqbO_YD3VLhC59edkQE-lRD7RI-yU_MEVD98tg0&e=> Website: https://ewh.ieee.org/soc/pses/ <https://urldefense.proofpoint.com/v2/url?u=https-3A__ewh.ieee.org_soc_pses_&d=DwMDaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=c9NR2mGfldry-2pM9Bbuww&m=AQbLI6yYUde_Q83E8xm-giFuu8VErE5y8fOfergBM5iZxYk2-pO-cenWPMbLLBpM&s=ORwQk6z-qsJYEmsPG1dXL9zJzd8_v-KXorv8oYvpzhI&e=> Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe)<https://urldefense.proofpoint.com/v2/url?u=https-3A__ewh.ieee.org_soc_pses_list.html&d=DwMDaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=c9NR2mGfldry-2pM9Bbuww&m=AQbLI6yYUde_Q83E8xm-giFuu8VErE5y8fOfergBM5iZxYk2-pO-cenWPMbLLBpM&s=MAXI7wWalzsZ4teDuRcUyv0b6dYvhshYdO1UqypFyxI&e=> List rules: https://ewh.ieee.org/soc/pses/listrules.html<https://urldefense.proofpoint.com/v2/url?u=https-3A__ewh.ieee.org_soc_pses_listrules.html&d=DwMDaQ&c=euGZstcaTDllvimEN8b7jXrwqOf-v5A_CdpgnVfiiMM&r=c9NR2mGfldry-2pM9Bbuww&m=AQbLI6yYUde_Q83E8xm-giFuu8VErE5y8fOfergBM5iZxYk2-pO-cenWPMbLLBpM&s=_IkG3VV27j8mAb1M5kLgwM93RLsTRWzSj2NBG_3oXzM&e=> For help, send mail to the list administrators: Mike Sherman at: msherma...@comcast.net<mailto:msherma...@comcast.net> Rick Linford at: linf...@ieee.org<mailto:linf...@ieee.org> For policy questions, send mail to: Jim Bacher at: j.bac...@ieee.org<mailto:j.bac...@ieee.org> To unsubscribe from the EMC-PSTC list, click the following link: https://listserv
Re: [PSES] thoughts on ESD test lab problems
That's right. It is good to call attention to problems that may well be deeply hidden or not recognized as a possibility, but it is necessary to concentrate on the facts and leave out peripheral matters that don't help to deal with the issue. On 2023-08-11 14:28, Larry K. Stillings wrote: You could certainly word this in a different way that doesn’t generalize how “most” test labs are bad and/or incompetent. How about in the future you find a different way to word things. - 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 All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe) List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: msherma...@comcast.net Rick Linford at: linf...@ieee.org For policy questions, send mail to: Jim Bacher: _ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1
Re: [PSES] thoughts on ESD test lab problems
Well said, Larry. Thanks, Jack Murphy DEKA Research & Development Corporation 340 Commercial Street Manchester, NH 03101 603-669-5139 (x6669) jmur...@dekaresearch.com<mailto:jmur...@dekaresearch.com> From: Larry K. Stillings Sent: Friday, August 11, 2023 9:29 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [External]: Re: [PSES] thoughts on ESD test lab problems Doug, Your once-a-year lab bashing is offensive, some years you do it more and honestly I'm tired of not saying something about it. It's especially offensive to people like myself whom has been running test labs for the last 33 years and pride myself in the work we have provided to our customers over that time. I could put up posts about bad EMC consultants that have been at our laboratory and provided expensive misguided information to our customers, or no solution at all to their EMC issues, however I choose not to stoop to your level. Categorizing test labs based on your limited experience (my guess is you've only been to a few labs, compared to how many there are in the USA and abroad) to make yourself look good continues to be ridiculously petty. You could certainly word this in a different way that doesn't generalize how "most" test labs are bad and/or incompetent. How about in the future you find a different way to word things. Larry K. Stillings Compliance Worldwide, Inc. Test Locally, Sell Globally and Launch Your Products Around the World! FCC - Wireless - Telecom - CE Marking - International Approvals - Product Safety 357 Main Street Sandown, NH 03873 (603) 887 3903 Fax 887-6445 complianceworldwide.com<https://complianceworldwide.com> <https://complianceworldwide.com> Privileged/Confidential Information may be contained in this message. If you are not the addressee indicated in this message (or responsible for delivery of the message to such person), you may not copy or deliver this message to anyone. In such case, you should destroy this message and kindly notify the sender by reply email. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of my firm shall be understood as neither given nor endorsed by it. From: doug emcesd.com Sent: Thursday, August 10, 2023 7:34 PM To: EMC-PSTC@LISTSERV.IEEE.ORG<mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] thoughts on ESD test lab problems Hi All, Just a couple of thoughts on what a good lab should do for ESD testing and how to protect yourself as a client from test problems. 1) Bring an Ohmmeter with you to the lab and measure the resistance from the Horizontal Coupling Plane to the Ground Reference Plane. It should be about 2X 470 K. I have seen both commercial test labs and private labs where these resistors are open which can cause a product failure. A good lab should measure this value every morning and report the result in your test report.. 2) The vacuum relay in the ESD simulators have a limited life after which the current waveform becomes quite variable and at that point cannot give an accurate test of your equipment. Having a valid calibration sticker is close to useless as the condition can develop quickly. I have personally seen a rented simulator with a valid calibration sticker have this problem with its current waveform all over the place from one discharge to another. A good test lab will verify this is not happening at the beginning of each day. You as a client can tell from a distance by just making a small antenna by extending a coax center conductor 6 inches pass the shield to make a small antenna. Better would be to make a TEM antenna which does not color its output by its resonances. Connect the antenna to a scope of at least 4 GSa/sec sampling rate, preferably higher. You don't really care what waveform you get, say from 6 feet away, but each discharge of a series of ten should look the same. More to come! Most test labs I have used over the years made at least one mistake that affected the test results. I have had disagreements with labs, never lost one of them. Doug 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 All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/<https://www.mail-archive.com/emc-pstc@listserv.ieee.org/%20> Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe)<https://ewh.ieee.org/soc/pses/list.html> List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: msherma...@comcast.net<mailto:msherma...@comcast.net> Rick Linford
Re: [PSES] thoughts on ESD test lab problems
Doug, Your once-a-year lab bashing is offensive, some years you do it more and honestly I'm tired of not saying something about it. It's especially offensive to people like myself whom has been running test labs for the last 33 years and pride myself in the work we have provided to our customers over that time. I could put up posts about bad EMC consultants that have been at our laboratory and provided expensive misguided information to our customers, or no solution at all to their EMC issues, however I choose not to stoop to your level. Categorizing test labs based on your limited experience (my guess is you've only been to a few labs, compared to how many there are in the USA and abroad) to make yourself look good continues to be ridiculously petty. You could certainly word this in a different way that doesn't generalize how "most" test labs are bad and/or incompetent. How about in the future you find a different way to word things. Larry K. Stillings Compliance Worldwide, Inc. Test Locally, Sell Globally and Launch Your Products Around the World! FCC - Wireless - Telecom - CE Marking - International Approvals - Product Safety 357 Main Street Sandown, NH 03873 (603) 887 3903 Fax 887-6445 complianceworldwide.com<https://complianceworldwide.com> <https://complianceworldwide.com> Privileged/Confidential Information may be contained in this message. If you are not the addressee indicated in this message (or responsible for delivery of the message to such person), you may not copy or deliver this message to anyone. In such case, you should destroy this message and kindly notify the sender by reply email. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of my firm shall be understood as neither given nor endorsed by it. From: doug emcesd.com Sent: Thursday, August 10, 2023 7:34 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] thoughts on ESD test lab problems Hi All, Just a couple of thoughts on what a good lab should do for ESD testing and how to protect yourself as a client from test problems. 1. Bring an Ohmmeter with you to the lab and measure the resistance from the Horizontal Coupling Plane to the Ground Reference Plane. It should be about 2X 470 K. I have seen both commercial test labs and private labs where these resistors are open which can cause a product failure. A good lab should measure this value every morning and report the result in your test report.. 2. The vacuum relay in the ESD simulators have a limited life after which the current waveform becomes quite variable and at that point cannot give an accurate test of your equipment. Having a valid calibration sticker is close to useless as the condition can develop quickly. I have personally seen a rented simulator with a valid calibration sticker have this problem with its current waveform all over the place from one discharge to another. A good test lab will verify this is not happening at the beginning of each day. You as a client can tell from a distance by just making a small antenna by extending a coax center conductor 6 inches pass the shield to make a small antenna. Better would be to make a TEM antenna which does not color its output by its resonances. Connect the antenna to a scope of at least 4 GSa/sec sampling rate, preferably higher. You don't really care what waveform you get, say from 6 feet away, but each discharge of a series of ten should look the same. More to come! Most test labs I have used over the years made at least one mistake that affected the test results. I have had disagreements with labs, never lost one of them. Doug [https://lh4.googleusercontent.com/_HuR3Ky2TF_XhFHyxnYRmiq7nHQldnMsPNYFaLG6kb5T4y8MeCe-BDC_BscJtSFgszSSjssihHS-pjM3-jwNP8S0CwE-gN8fsRsPkojiAlmpBwb20vIVizS-siCUywW_jqrefbVr] 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 All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/<https://www.mail-archive.com/emc-pstc@listserv.ieee.org/%20> Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe)<https://ewh.ieee.org/soc/pses/list.html> List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: msherma...@comcast.net<mailto:msherma...@comcast.net> Rick Linford at: linf...@ieee.org<mailto:linf...@ieee.org> For policy questions, send mail to: Jim Bacher at: j.bac...@ieee.org<mailto:j.bac...@ieee.org> To unsubscribe from the EMC-PSTC list, click
[PSES] thoughts on ESD test lab problems
Hi All, Just a couple of thoughts on what a good lab should do for ESD testing and how to protect yourself as a client from test problems. 1. Bring an Ohmmeter with you to the lab and measure the resistance from the Horizontal Coupling Plane to the Ground Reference Plane. It should be about 2X 470 K. I have seen both commercial test labs and private labs where these resistors are open which can cause a product failure. A good lab should measure this value every morning and report the result in your test report.. 2. The vacuum relay in the ESD simulators have a limited life after which the current waveform becomes quite variable and at that point cannot give an accurate test of your equipment. Having a valid calibration sticker is close to useless as the condition can develop quickly. I have personally seen a rented simulator with a valid calibration sticker have this problem with its current waveform all over the place from one discharge to another. A good test lab will verify this is not happening at the beginning of each day. You as a client can tell from a distance by just making a small antenna by extending a coax center conductor 6 inches pass the shield to make a small antenna. Better would be to make a TEM antenna which does not color its output by its resonances. Connect the antenna to a scope of at least 4 GSa/sec sampling rate, preferably higher. You don't really care what waveform you get, say from 6 feet away, but each discharge of a series of ten should look the same. More to come! Most test labs I have used over the years made at least one mistake that affected the test results. I have had disagreements with labs, never lost one of them. Doug [https://lh4.googleusercontent.com/_HuR3Ky2TF_XhFHyxnYRmiq7nHQldnMsPNYFaLG6kb5T4y8MeCe-BDC_BscJtSFgszSSjssihHS-pjM3-jwNP8S0CwE-gN8fsRsPkojiAlmpBwb20vIVizS-siCUywW_jqrefbVr] - 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 All emc-pstc postings are archived and searchable on the web at: https://www.mail-archive.com/emc-pstc@listserv.ieee.org/ Website: https://ewh.ieee.org/soc/pses/ Instructions: https://ewh.ieee.org/soc/pses/list.html (including how to unsubscribe) List rules: https://ewh.ieee.org/soc/pses/listrules.html For help, send mail to the list administrators: Mike Sherman at: msherma...@comcast.net Rick Linford at: linf...@ieee.org For policy questions, send mail to: Jim Bacher: _ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1
