Re: EN 50141 and EN 61000-4-6
I had to laugh when I saw the comparison between EMC and dentistry...How appropriate..!! From: John Woodgate Reply-To: John Woodgate To: emc-p...@majordomo.ieee.org Subject: Re: EN 50141 and EN 61000-4-6 Date: Mon, 14 Jan 2002 14:32:29 + I read in !emc-pstc that CE-test - Ing. Gert Gremmen - ce-marking and more... wrote (in ) about 'EN 50141 and EN 61000-4-6', on Mon, 14 Jan 2002: >If I would not advocate testing I would be a >bad entrepreneur/ If I would recommend clearly >unnecessary testing I would loose customers. I was *extremely* careful not to suggest otherwise. My concern is that, in some cases, the customers don't have enough knowledge to determine what is even 'clearly' unnecessary.' > >The same is true for dentists curing your dents. Pardon? (;-) >Did YOU actually check every hole in your teeth >really existed ? Yes, as it happens. > Or did you never go to the >dentist because no authority demands it. ;<)) Also yes. I am lucky to have extraordinarily resistant enamel on my teeth, and have to visit the dentist only at intervals of many years, in spite of being encouraged by them to do so every six months. > >It is the difference between good and bad test houses >to help selecting test suites for unknowing customers >(!??!) that other otherwise choose for >short time gains and long time losses. Again, I was careful to say that as well. > >And, as you should know, testing costs are important >for very small companies only. I don't agree, not because you are necessarily wrong but because many larger companies themselves don't agree. Yes, my interests lie mostly with SMEs, but I have advised very large companies and they are by no means complacent about testing costs. >Costs for EMC serial production >etc. are neglect able if designed in, from the start. This is true for *large volume products*, like TV sets. But it is not applicable to a large company that makes, for example, a very wide range of professional-use products, each of which is made in quantities not exceeding 1000 or so. >The gain from compliant equipment in terms of quality, >product life time and need for service can easily >be much higher then all testing suites I can imagine. I don't see how EMC conformity affects 'quality', life time and need for service. > >And there is much more to test than only EMC ! Of curse, safety has to be included, and safety conformity MAY affect 'quality' and 'need for service'. Product life-time is mostly determined by market forces (fashion and/or new versions of Windows) rather than technical end-of-life. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. _ Send and receive Hotmail on your mobile device: http://mobile.msn.com --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: ENV 50141 and EN 61000-4-6
A proposed amendment to EN50130-4 invokes EN61000-4-6 and clarifies other problems. Unfortunately it also calls out RF radiated immunity to 2GHz. Meanwhile, with EN50131-4's exceptions to ENV 50141, the switch to EN61000-4-5 is a moot point. David -Original Message- From: John Juhasz [mailto:jjuh...@fiberoptions.com] Sent: Monday, January 14, 2002 3:12 PM To: 'richwo...@tycoint.com'; emc-p...@majordomo.ieee.org Subject: RE: EN 50141 and EN 61000-4-6 Ditto here too. John Juhasz Fiber Options -Original Message- From: richwo...@tycoint.com [mailto:richwo...@tycoint.com] Sent: Monday, January 14, 2002 2:24 PM To: emc-p...@majordomo.ieee.org Subject: RE: EN 50141 and EN 61000-4-6 We test to EN50130-4 and we use EN61000-4-6 basud upon our understanding that ENV 50141 is withdrawn (see forward) and replaced by EN61000-4-6. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Mavis, Robert [mailto:rma...@pelco.com] Sent: Monday, January 14, 2002 11:09 AM To: cet...@cetest.nl; John Woodgate; emc-p...@majordomo.ieee.org Subject: RE: EN 50141 and EN 61000-4-6 So what do I do? Follow the EN 50130-4 : 1996 standard that states;" The test apparatus procedure shall be as described in ENV 50141 : 1993, with the following modifications and clarifications taken into account." or do I substitute EN 61000-4-6 in place of ENV 50141. -Original Message- From: CE-test - Ing. Gert Gremmen - ce-marking and more... [mailto:cet...@cetest.nl] Sent: Saturday, January 12, 2002 10:55 AM To: Mavis, Robert; John Woodgate; emc-p...@majordomo.ieee.org Subject: RE: EN 50141 and EN 61000-4-6 It looks as if you are right, but in the case of any ENV version of a standard, this calling out is incorrect. Any ENV standard is NOT a standard. It was never meant to be used as a standard but temporarily. The EN version following it WAS. However, in this case the EN 50141 was not published, so the only alternative is the EN 61000-4-6. The ENV version, as it says itself, automatically becomes non-existent as soon as its successor is published. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: owner-emc-p...@majordomo.ieee.org >>[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Mavis, Robert >>Sent: Saturday, January 12, 2002 4:55 AM >>To: John Woodgate; emc-p...@majordomo.ieee.org >>Subject: RE: EN 50141 and EN 61000-4-6 >> >> >> >>John, >> >>Even though the ENV is a pre-standard, if a Product Family >>Standard calls it >>out you must test to it. Am I not correct. >>Case in point, EN 50130-4 Product Family Standard for Alarm Systems calls >>out specifically ENV 50141 not EN 61000-4-6. >> >>-Original Message- >>From: John Woodgate [mailto:j...@jmwa.demon.co.uk] >>Sent: Friday, January 11, 2002 9:29 AM >>To: emc-p...@majordomo.ieee.org >>Subject: Re: EN 50141 and EN 61000-4-6 >> >> >> >>I read in !emc-pstc that Chris Chileshe >>wrote (in <01c19a92.f4398e80.chris.chile...@ultronics.co.uk>) about 'EN >>50141 and EN 61000-4-6', on Fri, 11 Jan 2002: >>>I am testing to the generic immunity standard EN 61000-6-2 >>>which refers to EN 61000-4-6 for immunity to conducted >>>disturbances induced by radio-frequency fields. >>> >>>A query has arisen that EN 50141 is missing from my list of >>>tests. Is my understanding correct that these two standards >>>are essentially the same? I do not have a copy of either and >>>currently awaiting delivery of EN 61000-4-6 which I have >>>recently purchased. >> >>50141 is an ENV (a 'pre-standard'), not an EN and is not called up by >>EN61000-6-2. Whoever threatened you with 'EN50141' is unaware of the >>facts. If it was a test-house, get another one! >>-- >>Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product S
SV: EN 50141 and EN 61000-4-6
EN 50130-4 is a CENELEC document and I assume ENV50141 also was a CENELEC document. When CELELEC tells us that EN61000-4-6 (which also is a CENELEC document) replaces ENV50141, I can't see why we still should use it. OK, CENELEC have been busy with other things instead of upgrading EN50130-4. I cases like this, we have to be some kind of pragmatic . Amund -Opprinnelig melding- Fra: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]På vegne av Kevin Harris Sendt: 14. januar 2002 18:14 Til: EMC-PSTC (E-mail) Emne: RE: EN 50141 and EN 61000-4-6 Hello Robert, Clearly, for absolute correctness you follow the ENV because that is what is called out in the standard, and the section in EN 50130-4 on "Dated references " requires you use it. However, if you document your substitution for the more recent document I don't believe any enforcement agency would (or could) fault you. Best Regards, Kevin Harris Manager, Approval Services Digital Security Controls 3301 Langstaff Road Concord, Ontario CANADA L4K 4L2 Tel: +1 905 760 3000 Ext. 2378 Fax +1 905 760 3020 Email: harr...@dscltd.com -Original Message- From: Mavis, Robert [mailto:rma...@pelco.com] Sent: Monday, January 14, 2002 11:09 AM To: cet...@cetest.nl; John Woodgate; emc-p...@majordomo.ieee.org Subject:RE: EN 50141 and EN 61000-4-6 So what do I do? Follow the EN 50130-4 : 1996 standard that states;" The test apparatus procedure shall be as described in ENV 50141 : 1993, with the following modifications and clarifications taken into account." or do I substitute EN 61000-4-6 in place of ENV 50141. -Original Message- From: CE-test - Ing. Gert Gremmen - ce-marking and more... [mailto:cet...@cetest.nl] Sent: Saturday, January 12, 2002 10:55 AM To: Mavis, Robert; John Woodgate; emc-p...@majordomo.ieee.org Subject: RE: EN 50141 and EN 61000-4-6 It looks as if you are right, but in the case of any ENV version of a standard, this calling out is incorrect. Any ENV standard is NOT a standard. It was never meant to be used as a standard but temporarily. The EN version following it WAS. However, in this case the EN 50141 was not published, so the only alternative is the EN 61000-4-6. The ENV version, as it says itself, automatically becomes non-existent as soon as its successor is published. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: owner-emc-p...@majordomo.ieee.org >>[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Mavis, Robert >>Sent: Saturday, January 12, 2002 4:55 AM >>To: John Woodgate; emc-p...@majordomo.ieee.org >>Subject: RE: EN 50141 and EN 61000-4-6 >> >> >> >>John, >> >>Even though the ENV is a pre-standard, if a Product Family >>Standard calls it >>out you must test to it. Am I not correct. >>Case in point, EN 50130-4 Product Family Standard for Alarm Systems calls >>out specifically ENV 50141 not EN 61000-4-6. >> >>-Original Message- >>From: John Woodgate [mailto:j...@jmwa.demon.co.uk] >>Sent: Friday, January 11, 2002 9:29 AM >>To: emc-p...@majordomo.ieee.org >>Subject: Re: EN 50141 and EN 61000-4-6 >> >> >> >>I read in !emc-pstc that Chris Chileshe >>wrote (in <01c19a92.f4398e80.chris.chile...@ultronics.co.uk>) about 'EN >>50141 and EN 61000-4-6', on Fri, 11 Jan 2002: >>>I am testing to the generic immunity standard EN 61000-6-2 >>>which refers to EN 61000-4-6 for immunity to conducted >>>disturbances induced by radio-frequency fields. >>> >>>A query has arisen that EN 50141 is missing from my list of >>>tests. Is my understanding correct that these two standards >>>are essentially the same? I do not have a copy of either and >>>currently awaiting delivery of EN 61000-4-6 which I have >>>recently purchased. >> >>50141 is an ENV (a 'pre-standard'), not an EN and is not called up by >>EN61000-6-2. Whoever threatened you with 'EN50141' is unaware of the >>facts. If it was a test-house, get another one! >>-- >>Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived
Re: EN 50141 and EN 61000-4-6
I read in !emc-pstc that Mavis, Robert wrote (in ) about 'EN 50141 and EN 61000-4-6', on Mon, 14 Jan 2002: >So what do I do? Follow the EN 50130-4 : 1996 standard that states;" The >test apparatus procedure shall be as described in ENV 50141 : 1993, with the >following modifications and clarifications taken into account." >or do I substitute EN 61000-4-6 in place of ENV 50141. Decide which of the two standards you prefer to use, and record the decision and the reasoning leading to it. That demonstrates due diligence in a situation in which you should never have been placed. IEC/EN50130-4 should have been corrected by now; there has been AMPLE time. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EN 50141 and EN 61000-4-6
Ditto here too. John Juhasz Fiber Options -Original Message- From: richwo...@tycoint.com [mailto:richwo...@tycoint.com] Sent: Monday, January 14, 2002 2:24 PM To: emc-p...@majordomo.ieee.org Subject: RE: EN 50141 and EN 61000-4-6 We test to EN50130-4 and we use EN61000-4-6 basud upon our understanding that ENV 50141 is withdrawn (see forward) and replaced by EN61000-4-6. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Mavis, Robert [mailto:rma...@pelco.com] Sent: Monday, January 14, 2002 11:09 AM To: cet...@cetest.nl; John Woodgate; emc-p...@majordomo.ieee.org Subject: RE: EN 50141 and EN 61000-4-6 So what do I do? Follow the EN 50130-4 : 1996 standard that states;" The test apparatus procedure shall be as described in ENV 50141 : 1993, with the following modifications and clarifications taken into account." or do I substitute EN 61000-4-6 in place of ENV 50141. -Original Message- From: CE-test - Ing. Gert Gremmen - ce-marking and more... [mailto:cet...@cetest.nl] Sent: Saturday, January 12, 2002 10:55 AM To: Mavis, Robert; John Woodgate; emc-p...@majordomo.ieee.org Subject: RE: EN 50141 and EN 61000-4-6 It looks as if you are right, but in the case of any ENV version of a standard, this calling out is incorrect. Any ENV standard is NOT a standard. It was never meant to be used as a standard but temporarily. The EN version following it WAS. However, in this case the EN 50141 was not published, so the only alternative is the EN 61000-4-6. The ENV version, as it says itself, automatically becomes non-existent as soon as its successor is published. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: owner-emc-p...@majordomo.ieee.org >>[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Mavis, Robert >>Sent: Saturday, January 12, 2002 4:55 AM >>To: John Woodgate; emc-p...@majordomo.ieee.org >>Subject: RE: EN 50141 and EN 61000-4-6 >> >> >> >>John, >> >>Even though the ENV is a pre-standard, if a Product Family >>Standard calls it >>out you must test to it. Am I not correct. >>Case in point, EN 50130-4 Product Family Standard for Alarm Systems calls >>out specifically ENV 50141 not EN 61000-4-6. >> >>-Original Message- >>From: John Woodgate [mailto:j...@jmwa.demon.co.uk] >>Sent: Friday, January 11, 2002 9:29 AM >>To: emc-p...@majordomo.ieee.org >>Subject: Re: EN 50141 and EN 61000-4-6 >> >> >> >>I read in !emc-pstc that Chris Chileshe >>wrote (in <01c19a92.f4398e80.chris.chile...@ultronics.co.uk>) about 'EN >>50141 and EN 61000-4-6', on Fri, 11 Jan 2002: >>>I am testing to the generic immunity standard EN 61000-6-2 >>>which refers to EN 61000-4-6 for immunity to conducted >>>disturbances induced by radio-frequency fields. >>> >>>A query has arisen that EN 50141 is missing from my list of >>>tests. Is my understanding correct that these two standards >>>are essentially the same? I do not have a copy of either and >>>currently awaiting delivery of EN 61000-4-6 which I have >>>recently purchased. >> >>50141 is an ENV (a 'pre-standard'), not an EN and is not called up by >>EN61000-6-2. Whoever threatened you with 'EN50141' is unaware of the >>facts. If it was a test-house, get another one! >>-- >>Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.o
RE: EN 50141 and EN 61000-4-6
We test to EN50130-4 and we use EN61000-4-6 basud upon our understanding that ENV 50141 is withdrawn (see forward) and replaced by EN61000-4-6. Richard Woods Sensormatic Electronics Tyco International -Original Message- From: Mavis, Robert [mailto:rma...@pelco.com] Sent: Monday, January 14, 2002 11:09 AM To: cet...@cetest.nl; John Woodgate; emc-p...@majordomo.ieee.org Subject: RE: EN 50141 and EN 61000-4-6 So what do I do? Follow the EN 50130-4 : 1996 standard that states;" The test apparatus procedure shall be as described in ENV 50141 : 1993, with the following modifications and clarifications taken into account." or do I substitute EN 61000-4-6 in place of ENV 50141. -Original Message- From: CE-test - Ing. Gert Gremmen - ce-marking and more... [mailto:cet...@cetest.nl] Sent: Saturday, January 12, 2002 10:55 AM To: Mavis, Robert; John Woodgate; emc-p...@majordomo.ieee.org Subject: RE: EN 50141 and EN 61000-4-6 It looks as if you are right, but in the case of any ENV version of a standard, this calling out is incorrect. Any ENV standard is NOT a standard. It was never meant to be used as a standard but temporarily. The EN version following it WAS. However, in this case the EN 50141 was not published, so the only alternative is the EN 61000-4-6. The ENV version, as it says itself, automatically becomes non-existent as soon as its successor is published. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: owner-emc-p...@majordomo.ieee.org >>[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Mavis, Robert >>Sent: Saturday, January 12, 2002 4:55 AM >>To: John Woodgate; emc-p...@majordomo.ieee.org >>Subject: RE: EN 50141 and EN 61000-4-6 >> >> >> >>John, >> >>Even though the ENV is a pre-standard, if a Product Family >>Standard calls it >>out you must test to it. Am I not correct. >>Case in point, EN 50130-4 Product Family Standard for Alarm Systems calls >>out specifically ENV 50141 not EN 61000-4-6. >> >>-Original Message- >>From: John Woodgate [mailto:j...@jmwa.demon.co.uk] >>Sent: Friday, January 11, 2002 9:29 AM >>To: emc-p...@majordomo.ieee.org >>Subject: Re: EN 50141 and EN 61000-4-6 >> >> >> >>I read in !emc-pstc that Chris Chileshe >>wrote (in <01c19a92.f4398e80.chris.chile...@ultronics.co.uk>) about 'EN >>50141 and EN 61000-4-6', on Fri, 11 Jan 2002: >>>I am testing to the generic immunity standard EN 61000-6-2 >>>which refers to EN 61000-4-6 for immunity to conducted >>>disturbances induced by radio-frequency fields. >>> >>>A query has arisen that EN 50141 is missing from my list of >>>tests. Is my understanding correct that these two standards >>>are essentially the same? I do not have a copy of either and >>>currently awaiting delivery of EN 61000-4-6 which I have >>>recently purchased. >> >>50141 is an ENV (a 'pre-standard'), not an EN and is not called up by >>EN61000-6-2. Whoever threatened you with 'EN50141' is unaware of the >>facts. If it was a test-house, get another one! >>-- >>Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. ---
Re: EN 50141 and EN 61000-4-6
I read in !emc-pstc that CE-test - Ing. Gert Gremmen - ce-marking and more... wrote (in ) about 'EN 50141 and EN 61000-4-6', on Mon, 14 Jan 2002: >If I would not advocate testing I would be a >bad entrepreneur/ If I would recommend clearly >unnecessary testing I would loose customers. I was *extremely* careful not to suggest otherwise. My concern is that, in some cases, the customers don't have enough knowledge to determine what is even 'clearly' unnecessary.' > >The same is true for dentists curing your dents. Pardon? (;-) >Did YOU actually check every hole in your teeth >really existed ? Yes, as it happens. > Or did you never go to the >dentist because no authority demands it. ;<)) Also yes. I am lucky to have extraordinarily resistant enamel on my teeth, and have to visit the dentist only at intervals of many years, in spite of being encouraged by them to do so every six months. > >It is the difference between good and bad test houses >to help selecting test suites for unknowing customers >(!??!) that other otherwise choose for >short time gains and long time losses. Again, I was careful to say that as well. > >And, as you should know, testing costs are important >for very small companies only. I don't agree, not because you are necessarily wrong but because many larger companies themselves don't agree. Yes, my interests lie mostly with SMEs, but I have advised very large companies and they are by no means complacent about testing costs. >Costs for EMC serial production >etc. are neglect able if designed in, from the start. This is true for *large volume products*, like TV sets. But it is not applicable to a large company that makes, for example, a very wide range of professional-use products, each of which is made in quantities not exceeding 1000 or so. >The gain from compliant equipment in terms of quality, >product life time and need for service can easily >be much higher then all testing suites I can imagine. I don't see how EMC conformity affects 'quality', life time and need for service. > >And there is much more to test than only EMC ! Of curse, safety has to be included, and safety conformity MAY affect 'quality' and 'need for service'. Product life-time is mostly determined by market forces (fashion and/or new versions of Windows) rather than technical end-of-life. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EMC-related safety issues
I read in !emc-pstc that cherryclo...@aol.com wrote (in <14b.7351131.297 42...@aol.com>) about 'EMC-related safety issues', on Mon, 14 Jan 2002: >I'm sure I said in my original posting on this example, that the HCMOS was >'hard switching' and not producing a sine wave. A hot device was, of > course, >the first thing I looked for, and didn't find any. See the additional >information above. > Yes, you did, BUT I wrote: > > >> The absence of harmonics even suggests that this gate was producing a >> sine-wave, which makes the figures even higher and less credible. The presence of the high-Q resonant structure that you describe is clearly the real reason why no harmonics were observed. It is not only a good antenna *but it very probably cannot radiate odd harmonics*, which should be the only ones present if the drive waveform was square. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Safety of microwave ovens
Hi, Our over-the-cooking-range microwave oven has not been functioning for some time now, and we have been using a table-top microwave oven instead. Recently, I wanted to replace the microwave, but my wife said she preferred the existing arrangement. Her contention is that she often uses microwave and cooking range simultaneously, and this makes her stand in close proximity to the microwave. She has concerns about RF leakage from the microwave, and feels it can be harmful. I have not come across any information on the safety of the domestic microwave ovens. Is there anyone who has actually measured the RF leakage from the microwave, or can lead me to the other research information on the subject. All replies will be greatly appreciated. Regards, Ravinder Email: ajm...@us.ibm.com *** Always do right. This will gratify some people and astonish the rest. Mark Twain --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: EN 50141 and EN 61000-4-6
Hello Robert, Clearly, for absolute correctness you follow the ENV because that is what is called out in the standard, and the section in EN 50130-4 on "Dated references " requires you use it. However, if you document your substitution for the more recent document I don't believe any enforcement agency would (or could) fault you. Best Regards, Kevin Harris Manager, Approval Services Digital Security Controls 3301 Langstaff Road Concord, Ontario CANADA L4K 4L2 Tel: +1 905 760 3000 Ext. 2378 Fax +1 905 760 3020 Email: harr...@dscltd.com -Original Message- From: Mavis, Robert [mailto:rma...@pelco.com] Sent: Monday, January 14, 2002 11:09 AM To: cet...@cetest.nl; John Woodgate; emc-p...@majordomo.ieee.org Subject:RE: EN 50141 and EN 61000-4-6 So what do I do? Follow the EN 50130-4 : 1996 standard that states;" The test apparatus procedure shall be as described in ENV 50141 : 1993, with the following modifications and clarifications taken into account." or do I substitute EN 61000-4-6 in place of ENV 50141. -Original Message- From: CE-test - Ing. Gert Gremmen - ce-marking and more... [mailto:cet...@cetest.nl] Sent: Saturday, January 12, 2002 10:55 AM To: Mavis, Robert; John Woodgate; emc-p...@majordomo.ieee.org Subject: RE: EN 50141 and EN 61000-4-6 It looks as if you are right, but in the case of any ENV version of a standard, this calling out is incorrect. Any ENV standard is NOT a standard. It was never meant to be used as a standard but temporarily. The EN version following it WAS. However, in this case the EN 50141 was not published, so the only alternative is the EN 61000-4-6. The ENV version, as it says itself, automatically becomes non-existent as soon as its successor is published. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: owner-emc-p...@majordomo.ieee.org >>[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Mavis, Robert >>Sent: Saturday, January 12, 2002 4:55 AM >>To: John Woodgate; emc-p...@majordomo.ieee.org >>Subject: RE: EN 50141 and EN 61000-4-6 >> >> >> >>John, >> >>Even though the ENV is a pre-standard, if a Product Family >>Standard calls it >>out you must test to it. Am I not correct. >>Case in point, EN 50130-4 Product Family Standard for Alarm Systems calls >>out specifically ENV 50141 not EN 61000-4-6. >> >>-Original Message- >>From: John Woodgate [mailto:j...@jmwa.demon.co.uk] >>Sent: Friday, January 11, 2002 9:29 AM >>To: emc-p...@majordomo.ieee.org >>Subject: Re: EN 50141 and EN 61000-4-6 >> >> >> >>I read in !emc-pstc that Chris Chileshe >>wrote (in <01c19a92.f4398e80.chris.chile...@ultronics.co.uk>) about 'EN >>50141 and EN 61000-4-6', on Fri, 11 Jan 2002: >>>I am testing to the generic immunity standard EN 61000-6-2 >>>which refers to EN 61000-4-6 for immunity to conducted >>>disturbances induced by radio-frequency fields. >>> >>>A query has arisen that EN 50141 is missing from my list of >>>tests. Is my understanding correct that these two standards >>>are essentially the same? I do not have a copy of either and >>>currently awaiting delivery of EN 61000-4-6 which I have >>>recently purchased. >> >>50141 is an ENV (a 'pre-standard'), not an EN and is not called up by >>EN61000-6-2. Whoever threatened you with 'EN50141' is unaware of the >>facts. If it was a test-house, get another one! >>-- >>Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Heal
RE: EN 50141 and EN 61000-4-6
So what do I do? Follow the EN 50130-4 : 1996 standard that states;" The test apparatus procedure shall be as described in ENV 50141 : 1993, with the following modifications and clarifications taken into account." or do I substitute EN 61000-4-6 in place of ENV 50141. -Original Message- From: CE-test - Ing. Gert Gremmen - ce-marking and more... [mailto:cet...@cetest.nl] Sent: Saturday, January 12, 2002 10:55 AM To: Mavis, Robert; John Woodgate; emc-p...@majordomo.ieee.org Subject: RE: EN 50141 and EN 61000-4-6 It looks as if you are right, but in the case of any ENV version of a standard, this calling out is incorrect. Any ENV standard is NOT a standard. It was never meant to be used as a standard but temporarily. The EN version following it WAS. However, in this case the EN 50141 was not published, so the only alternative is the EN 61000-4-6. The ENV version, as it says itself, automatically becomes non-existent as soon as its successor is published. Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: owner-emc-p...@majordomo.ieee.org >>[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Mavis, Robert >>Sent: Saturday, January 12, 2002 4:55 AM >>To: John Woodgate; emc-p...@majordomo.ieee.org >>Subject: RE: EN 50141 and EN 61000-4-6 >> >> >> >>John, >> >>Even though the ENV is a pre-standard, if a Product Family >>Standard calls it >>out you must test to it. Am I not correct. >>Case in point, EN 50130-4 Product Family Standard for Alarm Systems calls >>out specifically ENV 50141 not EN 61000-4-6. >> >>-Original Message- >>From: John Woodgate [mailto:j...@jmwa.demon.co.uk] >>Sent: Friday, January 11, 2002 9:29 AM >>To: emc-p...@majordomo.ieee.org >>Subject: Re: EN 50141 and EN 61000-4-6 >> >> >> >>I read in !emc-pstc that Chris Chileshe >>wrote (in <01c19a92.f4398e80.chris.chile...@ultronics.co.uk>) about 'EN >>50141 and EN 61000-4-6', on Fri, 11 Jan 2002: >>>I am testing to the generic immunity standard EN 61000-6-2 >>>which refers to EN 61000-4-6 for immunity to conducted >>>disturbances induced by radio-frequency fields. >>> >>>A query has arisen that EN 50141 is missing from my list of >>>tests. Is my understanding correct that these two standards >>>are essentially the same? I do not have a copy of either and >>>currently awaiting delivery of EN 61000-4-6 which I have >>>recently purchased. >> >>50141 is an ENV (a 'pre-standard'), not an EN and is not called up by >>EN61000-6-2. Whoever threatened you with 'EN50141' is unaware of the >>facts. If it was a test-house, get another one! >>-- >>Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org
RE: Car EMC, was bulk current injection testing
>-Original Message- >From: Cortland Richmond [mailto:cortland.richm...@alcatel.com] >Sent: Friday, January 11, 2002 9:47 AM >To: Ken Javor >Cc: George Stults; Chris Maxwell; scott@jci.com; >michael.sundst...@nokia.com; emc-p...@majordomo.ieee.org >Subject: Re: Car EMC, was bulk current injection testing > > > >A small antenna with a 45 Mhz source and mixer at the center >would retransmit a US >cellphone on its own receive frequency. Would that do what you want? > >Cortland - KA5S > >(What I write here is mine alone. >My employer does not >Concur, agree or else endorse >These words, their mood, or thought.) How many whimsical sig lines does Cortland have?! Ed Ed Price ed.pr...@cubic.com Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military & Avionics EMC Services Is Our Specialty Shake-Bake-Shock - Metrology - Reliability Analysis --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: EN50091-2:1995
IEC 62040-2 should have had a parallel vote in CENELEC as it was intended to replace EN 50091-2. That was not done which lead to a lot of confusion. The "under consideration" phrase was carried forward from EN 50091-2 to IEC 62040-2 in Annex D. The normative reference part of the IEC standard was corrected but the Annex wasnt. The next edition of IEC 62040-2 will have the proper corrections for all the"under consideration" type errors as well as a parallel vote in CENELEC so that there will be a EN 62040-2. IEC 62040-2 should have been turned into an EN and a lot of confusion would have been eliminated. The schedule for turning the IEC to an EN as listed below is quite ambicious to say the least. A CDV by December. It could happen but seeing as how we haven't scheduled a meeting to discuss the standard yet that does seem a little agressive. But hey stranger things have happened. Please let me know if you have further questions regarding this standard as I am involved with the committee that is doing the writing. John Woodgate To: emc-p...@majordomo.ieee.org Sent by: cc: owner-emc-pstc@majordomSubject: Re: EN50091-2:1995 o.ieee.org 01/11/2002 04:18 PM Please respond to John Woodgate I read in !emc-pstc that Sam Wismer wrote (in <000901c19ab1$7feb4ae0$0201a8c0@sam>) about 'EN50091-2:1995', on Fri, 11 Jan 2002: >I am reviewing EN50091-2:1995 to determine the immunity requirements for UPS >systems. According to the harmonized list, this is the correct version of >the standard under the EMCD. It calls for radiated emissions, IEC 801-2, -3 >and -4. It then says 801-5 is under consideration. Our customer is >requesting 801-5, but based on how I read the standard, it is not required >at this time. Could that be true? > The standard is seriously out-of-date. 801-5 was never published (but an unfinished version was issued as ENV50142), and the requirements in 801-2 to -4 have been considerably changed in the current IEC/EN 61000-4 series. Here is the (re-formatted) information from the CENELEC web site on the replacement: Project number 14872 Standard reference prEN62040-2 Reference document IEC 62040-2:200X Technical body CLC/TC 22X IEC/TC IEC/SC 22H Stage code Stage code date Stage code deadline Real next stage code 31 (2020) 2001-10-31 2002-06-30 32 (3020) Target enquiry Target approval Target ratification Target available 2003-06-30 2003-11-30 2004-03-31 Note 2001-10 decision: Work on future IEC 62040-2 to replace EN 50091-2:1995 * CDV expected December 2002 Title (EN) Uninterruptible power systems (UPS) -- Part 2: Electromagnetic compatibility (EMC) requirements Now, what should you do? IMO, you probably cannot just ignore the surge test, so I suggest you apply IEC61000-4-5, and explain in your technical file why you did that. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute:
Re: EMC-related news article
Those who are interested in Electromagnetic terrorism possibilities should read "Information Warfare: battles in cyberspace" by Richard E Overill in the IEE Computing and Control Engineering Journal,June 2001, pages 125-128. He also covers threats from hackers. Richard is a Senior Lecturer in Computer Science at Kings College London, where he collaborates in the research and consultancy work of the International Centre for Security Analysis (ICSA). His article concludes: "The threats to, vulnerabilities of, and impacts on critical national infrastructures (CNI) are real and capable of assessment, although in practice this is a complex and challenging task, the more so since information warfare possesses several characteristics of that are not shared by conventional warfare: it is global (there are no borders); it is precise (surgical strikes are possible); it is un-proportionate (the cost of attack is much less than the cost of defence). Some of the accounts of information warfare carried by the media have been exaggerated or are inaccurate, but this must not deflect us from addressing the crucial issues of defining, developing, and deploying critical infrastructure protection (CIP) policies and strategies." If you don't agree, don't complain to me - email him at: rich...@dcs.kcl.ac.uk or via the Web at: http://www.dcs.kcl.ac.uk/staff/richard -but better read his full article first! You might also be interested in visiting Metatech's pages at http://www.metatechcorp.com/USRI.htm and http://www.metatechcorp.com/EMIthr1/slide1.htm (I hope these links still work, I haven't tested them.) Regards, Keith Armstrong In a message dated 11/01/02 20:27:48 GMT Standard Time, cortland.richm...@alcatel.com writes: > Subj:EMC-related news article > Date:11/01/02 20:27:48 GMT Standard Time > From:cortland.richm...@alcatel.com (Cortland Richmond) > Sender:owner-emc-p...@majordomo.ieee.org > Reply-to: HREF="mailto:cortland.richm...@alcatel.com";>cortland.richm...@alcatel.com > (Cortland Richmond) > To:ken.ja...@emccompliance.com (Ken Javor) > CC:emc-p...@majordomo.ieee.org > > Finally, a voice of sanity in news articles about > electromagnetic vulnerability. The ABC online news > headline is > > High-Tech Robbery > Physicists Say > Electromagnetic-Aided > Robbery Limited to > Hollywood > > http://abcnews.go.com/sections/scitech/DailyNews/pinch020111.html > > Cortland > > (What I think; not my employer) >
Re: EMC-related safety issues
Dear Ken Sorry to be so late replying, but I have been unable to read any of the correspondence in this thread for a week. In an attempt to spare the emc-pstc more of our arguing I will not reply in detail to three of your emails, one from the 6th Jan, and two from the 7th Jan, because they all deal with what I think is the core issue: "Can the emissions from an 'intentional radiator' such as a laptop that is compliant with CISPR22 and/or FCC limits interfere with an electronic product that is not an intentional radio receiver and possibly cause a safety problem?" Have I summarised the issue correctly? I am of the opinion, and I think the other correspondents are too, that the answer is: "Yes they can in some circumstances but it should be unlikely these days". I think the reasons for this conclusion include... a) Products with compliant fields at 10 metres distance might have considerably stronger fields closer to, especially in their near field. b) The mandatory standards don't measure all the frequencies that could be emitted from the compliant laptop and possibly cause interference (e.g. audio frequency magnetic fields from fluctuating dc power supply currents can interfere directly with nearby audio or low-frequency transducer circuits). c) Some circuits are very sensitive (especially some transducer amplifiers), or not well-designed for RF immunity, or both at the same time. What do you think, Ken? What do the other emc-pstc members think? Can we please finish this debate now? Regards, Keith Armstrong PS: I will not be able to reply to postings in this thread for about another week.
Re: EMC-related safety issues
Dear Ken Sorry to have taken so long to reply to this. I haven't been able to read any of the contributions for a week. I have to say that I don't recognise myself, or the IEE's guide on EMC and Functional Safety or the 30+ respected and senior engineers who contributed to it, or the IEE itself, in any way whatsoever in your descriptions below. Have you read the IEEE's Ethical Policy? (That's the IEEE not the IEE). What do you think of it? Regards, Keith Armstrong PS: I will not be able to reply to postings in this thread for about another week. In a message dated 07/01/02 02:37:17 GMT Standard Time, ken.ja...@emccompliance.com writes: > Subj:Re: EMC-related safety issues > Date:07/01/02 02:37:17 GMT Standard Time > From:ken.ja...@emccompliance.com (Ken Javor) > To:cherryclo...@aol.com, j...@jmwa.demon.co.uk > CC:emc-p...@majordomo.ieee.org > > The question of ethics or morality is at the heart of this discussion which > makes it much more important than technical discussions about > electromagnetism, which is the ONLY reason I have pursued this so far. I > was critical of the IEE safety guide on MORAL grounds. It is part of the > morality which says that businessmen or producers are considered guilty > until proven innocent because of what they are - profit-making producers. > That it is immoral to make a profit and anyone doing so is taking advantage > of someone else. This is not the morality which built the USA into the > world's wealthiest nation, but it is the morality which will reduce us to > the most impecunious. The strict Muslim countries that have been in the > news of late forbid loaning of money at interest, because the Koran forbids > usury. It is no accident that these countries all belong to the third > world. Progress depends on the ability to raise capital. The most > efficient way to do that is for people who have profited from past ventures > to invest those profits in new ventures. That is what banks facilitate. > If there are no profits, then there is no money to borrow and to start a > venture and progress stops or becomes agonizingly slow. A policy which > says that producers are liable for unlimited damages without needing to > show defect or negligence is on a moral level with the prohibition of > lending money at interest. We have to decide if we wish to live in a > civilized world or not. That is a question of moral significance. > > The idea that businessmen are immoral greedy people who give no thought to > the quality of their products is an ugly lie spread by enemies of > capitalism. A little thought will show that businessmen who operate like > this do not stay in business long because their products get a bad > reputation. Certainly you can find examples of bad or ignorant behavior. > Does this justify policies which assume all businessmen are evil and that > they must be reined in by pure-hearted regulators? What makes the > regulators pure-hearted? That they don't make profit, but siphon profits > away? What is the cost of the regulation relative to the benefit? What > marvelous inventions didn't occur because the seed money necessary to > initiate a development wasn't there? > > When engineers make false claims that unintentional RE from ITE can cause > safety-critical circuits to fail catastrophically, we engage in another > moral transgression. We attempt to get a short term gain at the cost of > long term loss. The short term gain is to make ourselves and our > profession look more important. But the long term loss is that of the > little boy who cried wolf. After a long enough period of false alarms, we > will lose the respect and ear of management and if we must raise a REAL > issue, it will fall on deaf ears. I have no way of knowing, but I wonder > how many unfulfilled warnings the managers who OK'd the launch of 51L > (Challenger) had listened to prior to making their fateful decision. > >
Re: EMC-related safety issues
Dear Ken Sorry to have taken so long to reply to this. Pressure of work has kept me away from the thread for a week. I don't know where you get your maths from. The usual formula (commonly available in a number of variants) for the radiated emissions E in V/m at 10 metres due to a common-mode current is: E = 1.26 10^-4 (f.L.ICM) f = frequency in MHz L = length of the radiating cable in metres ICM = common-mode current in the cable in milliamps Using L = 1.5 metres (not a long cable) and f = 100MHz, I find that 92dBuV/m (= 40mV/m) can be created at 10 metres distance by a CM current of just 2mA. 2mA is a far cry from your "significant fraction of an Ampere of common mode rf current". Hence my serious concerns about your math. I also don't agree with a number of other things in your analysis below, especially as you finish by saying: "If you consider that any signal with information content carried by 2 mV is shielded, the issue becomes, once again, a non-problem." I don't think you can make the assumption that cables carrying low level signals are shielded. Remember that this thread began with a discussion of EMC-related safety issues, and where safety is involved one shouldn't make assumptions that everyone else designs equipment as well as you would like them to. If we consider a country such as the US with no mandatory EMC immunity regulations, and a measuring device that uses analogue technology and does not have to meet emissions standards, it is obvious that the lowest cost way to design and market it is to leave out all the shielding and filtering, and I would expect a proportion of manufacturers to do just that. I will spare the emc-pstc a longer email by not responding to the other issues I don't agree with at this time. Maybe other contributors would like to support your analysis below? or not. Regards, Keith Armstrong. PS: It will be another week before I can reply again to postings in this thread. In a message dated 07/01/02 02:46:46 GMT Standard Time, ken.ja...@emccompliance.com writes: > Subj:Re: EMC-related safety issues > Date:07/01/02 02:46:46 GMT Standard Time > From:ken.ja...@emccompliance.com (Ken Javor) > Sender:owner-emc-p...@majordomo.ieee.org > Reply-to: HREF="mailto:ken.ja...@emccompliance.com";>ken.ja...@emccompliance.com > (Ken Javor) > To:cherryclo...@aol.com > CC:emc-p...@majordomo.ieee.org > > > QUOTE: "And I don't think that 92dBuV/m is a high field strength to be > emitted by a PC placed nearby, or for a non-compliant laptop at 10 metres." > > You may not think so, but I am sorry, the numbers just don't add up. 92 > dBuV/m at 10 meters implies an effective radiated power of 5.3 mW. > Consider that the source is not an intentional antenna. It will have no > more directivity than a dipole and its efficiency will be much less since > it isn't matched to the source. If we simply assume no gain (meaning > matching losses just offset directivity) , that means 5.3 mW of rf power > are emitted from the EUT or its attached cables. If one makes the > reasonable assumption that it is common mode rf current which is radiating, > then the potential associated with rf power will be a small number of > millivolts (in the frequency domain). This in turn implies a significant > fraction of an Ampere of common mode rf current. A highly unlikely > situation! Once again, with an impossible conclusion, either the > assumption or the logic must be wrong. You can choose to disbelieve, but > please point out where the logic has gone awry. You have several times > cited Mr. Woodgate for non-constructive criticism. Now I am asking you, > don't give more hearsay: explain where my physics is incorrect. We are > engineers here, not pollsters. > > And if you are saying that specification level compliance at 10 meters can > scale up to 92 dBuV/m nearby, that is either false or misleading depending > on the frequency range. At the low end, say 30 MHz, the area subtended by > position near the offending PC isn't large enough to efficiently radiate or > couple the field (the wavelength is 10 meters, and the other gentleman's > antenna factor calculation assumed a tuned dipole antenna in order to get a > small antenna factor). So the field will not scale up as per your > prediction, and the pickup mechanism will be nowhere near the antenna > factor that gentleman calculated. In fact at 30 MHz your antenna factor > will be on the order of 20 dB or worse (assuming the mutual coupling length > to be 1 m). At the high end (near 1 GHz) you could be in the far field in > close and the field could scale up to a value of 92 dBuV/m, but the antenna > factor of a matched tuned dipole at 1 GHz is 26 dB so the potential from > that perfect antenna is 92 dBuV/m - 26 dB/m = 66 dBuV or 2 mV. If you > consider that any signal with information content carried by 2 mV is > shielded, the issue becomes, once again, a non-p
Re: EMC-related safety issues
Dear John Sorry to have taken so long to reply. We were talking about safety-related systems. The general approach is to add additional back-ups to the safety related system to provide it with necessary reliability as far as safety is concerned, as I had hoped the examples in the full version of my original reply would help to make clear. Such reliability improvement exercises might have nothing to do with improving the EMC of a product or of making its functionality more reliable. Safety engineers are not usually concerned about whether a product is reliable, merely that if it fails to function correctly (e.g. due to interference) then it should not become unsafe. Another example that does not involve a dual (or triple) electronic system with voting is a gas boiler control. These days, large commercial and industrial gas boilers are controlled by microprocessors taking inputs from a lot of sensors. We don't want to add to the cost by duplicating the electronic control systems and transducers using diverse technologies - as you so rightly pointed should be done to avoid what are known as 'common-cause failures'. So what we can do is use some good old fashioned engineering to ensure that if the controller goes haywire, the boiler shuts down safely. For instance, we can use a simple and well-understood type of gas valve that cuts the gas supply off if the flame goes out. No electronics, nothing to interfere with, but it stops the microprocessor from erroneously pumping out gas when the flame isn't lit because (for instance) someone is standing too near by talking on their cellphone. If the microprocessor turns the flame up too high for too long and the boiler could overheat, our old friends the pressure relief valve and thermal trip come to the rescue. By using these additional components (and considering a few more failure scenarios) we can use an unreliable and cheap microprocessor with terrible EMC immunity performance and yet have great safety performance. The reliability of the system might be poor, and customers might be always complaining about their boilers cutting out, but as I said safety engineers (and safety test labs) don't care if you have a poor product that nobody will be pleased with, as long as it is safe. The mistake that many people make is to confuse functional reliability (sometimes called availability or uptime, the reciprocal of downtime) with functional safety. A very unreliable and low-cost system can be a perfectly safe one, with appropriate design techniques. Regards, Keith Armstrong PS: It will be another week before I can reply again to postings in this thread. In a message dated 06/01/02 19:34:49 GMT Standard Time, j...@jmwa.demon.co.uk writes: > Subj:Re: EMC-related safety issues > Date:06/01/02 19:34:49 GMT Standard Time > From:j...@jmwa.demon.co.uk (John Woodgate) > Sender:owner-emc-p...@majordomo.ieee.org > Reply-to: mailto:j...@jmwa.demon.co.uk";>j...@jmwa.demon.co.uk > (John Woodgate) > To:emc-p...@majordomo.ieee.org > > I read in !emc-pstc that cherryclo...@aol.com wrote (in <162.6b92ca5.296 > 9c...@aol.com>) about 'EMC-related safety issues', on Sun, 6 Jan 2002: > >Yes, John, you are quite right in both your comments as far as you go: > > > >1) You are not the only person who can dramatise an issue so as to > encourage > >people to debate it; > > I don't know what you are referring to. I have 146 articles already read > in the thread: I don't see that the debate needs any encouragement. > > > >2) If you sold a single electronic safety-related circuit with a > failure > >probability of 10^ -9 to 100,000 customers the cumulative failure > >probability is indeed 10^ -4. As you correctly said, Olber's Paradox > does > >not apply in this area. > > > >But nevertheless this does not mean we need to make electronic > circuits with > >failure rates equal to or better than 10^ -9. As you have said (and I > agree) > >this would be a very difficult task indeed and likely to be very > expensive, > >especially for any product using software. > > > >So how do we square this particular circle? > > > >Those members who are familiar with safety engineering techniques will > be > >familiar with the idea of building very reliable systems up using a > number > >of independent systems or devices each with lower reliability. These > have > >various names, such as 'redundant channels' or 'duplicate channels' or > >'safety back-ups' or 'fail-safe circuits' and many others. > > > I don't see how this applies to the reduction of emissions or, > practicably, to the improvement of immunity. Do you envisage three > separate systems in every product, with majority voting? I suspect that > in terms of improving immunity, it would be ineffective, because a > disturbance that compromised one system would be very likely to > compromise at least o
Re: EMC-related safety issues
Dear John Sorry to have taken so long to reply. We will have to disagree over the educational value of the EMC + Compliance Journal's "Banana Skins" column. If you haven't seen anything that was CE marked but which was obviously not compliant, then I think you must be lucky. As I mentioned earlier, whenever EMC enforcers in the EU carry out random checks on products in the marketplace, they seem to find that around 30% are clearly not compliant (a broad-brush average, since it seems to depend on the type of product), and there have been some papers presented by such enforcers in recent years for which I will be pleased to provide such references as I have. Your 'unfoggy' replacement statement was good, but only relevant to carefully limited circumstances. I notice you included the lines: "...are extremely unlikely to cause malfunction of other equipment having the degree of immunity afforded by normal design practices." – but could you please define exactly what you mean by "extremely unlikely", "malfunction" and "normal design practices". It seems to me that in the end, your improved alternative statement still needs to use foggy' language after all. I am pleased that you agree with me that the debate in question – (which I seem to remember concerned whether "unintentional emitters" that are compliant with emissions standards when measured at 10 metres can interfere with electronic circuits which are not intentional radio receivers) – cannot be answered with a definitive yes or no. Everyone other than a single correspondent to this thread seem to have difficulty in accepting this basic and scientifically correct statement. As for the assertion that : "Doctors and surgeons kill people one at a time, but engineers do it by the thousand." - consider that in the EU in the mid-90's there were around 30,000 fires caused by failures in washing machines every year, a proportion of which resulted in property damage and a few end in deaths. An engineer who designs a faulty consumer product or vehicle can put thousands of lives at risk. Ask Ford and Firestone about the deaths (and the cost to their companies) of their recent engineering error in fitting the Ford Explorer with Firestone Wilderness tyres (maybe that should be tires). Maybe a more accurate statement (if a little foggier) would be "Doctors and surgeons kill people one at a time, but some engineers could do it by the thousand." Regards, Keith Armstrong PS: It will be another week before I can reply again to postings in this thread. In a message dated 06/01/02 19:34:57 GMT Standard Time, j...@jmwa.demon.co.uk writes: > Subj:Re: EMC-related safety issues > Date:06/01/02 19:34:57 GMT Standard Time > From:j...@jmwa.demon.co.uk (John Woodgate) > Sender:owner-emc-p...@majordomo.ieee.org > Reply-to: mailto:j...@jmwa.demon.co.uk";>j...@jmwa.demon.co.uk > (John Woodgate) > To:emc-p...@majordomo.ieee.org > > I read in !emc-pstc that cherryclo...@aol.com wrote (in <14b.6d4a617.296 > 9c...@aol.com>) about 'EMC-related safety issues', on Sun, 6 Jan 2002: > >Dear John > >The incubator I described was already on the EU market in the latter > half of > >the 1990s, when I helped to test and fix it. > > > >And I'm sorry to disappoint > > Inappropriate word; I'm not interested in scoring debating points but > exploring the approaches to 'EMC and Safety', which I think need to be > explored. > > >but I have already experienced several similar > >examples I could quote, such as the electric blanket that would change > its > >heat settings randomly when a bedside light was switched on or off, or > from > >other low-level mains transients. > >This is a potentially fatal issue for certain kinds of invalid, or > people > >who are blind drunk (surely no person reading this would ever be in > such a > >state) and by the way, this is not me being emotive again, > > I agree; what you have written here is not emotive. > >it was the > >expressed concern of the manufacturer and one of the reasons why they > called > >me in. They sacked their Technical Director over this incident. > >They also didn't do a product recall despite having an estimated > 100,000 > >products with the problem already out in the field. Of course, as a > >responsible engineer (and to cover my ass) I wrote them a letter > >recommending that they did a product recall (while thinking of the > designers > >of the Challenger Space Shuttle's infamous O-ring seals). > > > >I find that many independent EMC people have dozens of similar > examples, > >which they can't talk about very much because of commercial > confidentiality. > >This is one reason why the EMC + Compliance Journal > >(www.compliance-club.com) started its 'Banana Skins' column - to help > >educate practising engineers about real EMC engineering problems they > almost >
Re: EMC-related safety issues
Dear Ken and John Sorry to have taken so long to reply to your emails about my 200MHz oscillating HCMOS example. I hope it is OK to reply to you both in one email, too. Replying to Ken... My example was not an urban myth, it was a real example (although I didn't measure its RF field or estimate its ERP so can't vouch for their accuracy). It was an unlikely chain of events that caused the problem, and it was not the HCMOS device that was doing the actual radiating. The large PCB on which the HCMOS hex inverter was located had a 0.5 inch wide ground and power trace running all around its perimeter, one on each side of the two-layer PCB. Thin traces ran from these 'power buses' to all the ICs on the PCB. The dimensions of the perimeter traces were perfectly right for resonance at 200MHz (and there were no decouplers between the traces) and they made a wonderful rectangular frame antenna at that frequency too. The HCMOS device that suffered the unterminated gate was in the centre of the PCB and got its +5V from the trace at the top of the PCB, its 0V from the trace at the bottom, thereby making an excellent driver for the resonant circuit. The end result was a high-Q resonant 'tank' circuit being driven by the hard-switching device, and setting the basic oscillation frequency. Because the device was hard switching, it didn't heat up. Because the tank circuit had such high-Q and was also a great antenna it radiated the 200MHz component but not the other harmonics of the hard switching device. The result was a very efficient 200MHz transmitter design that RF transmitter designers would understand. I don't find it unusual that it could create quite strong field strengths. My point in making this example is that events can sometimes combine to catch designers out. Replying to John I'm sure I said in my original posting on this example, that the HCMOS was 'hard switching' and not producing a sine wave. A hot device was, of course, the first thing I looked for, and didn't find any. See the additional information above. Regards, Keith Armstrong PS: It will be another week before I can reply again to postings in this thread. > Date: 07/01/02 06:35:46 GMT Standard Time > From:j...@jmwa.demon.co.uk (John Woodgate) > Indeed, and assuming a 5 V supply, the current would be around 400 mA. > At 200 MHz, the dissipation would be several hundred milliwatts. > The absence of harmonics even suggests that this gate was producing a > sine-wave, which makes the figures even higher and less credible. In a message dated 07/01/02 02:37:12 GMT Standard Time, ken.ja...@emccompliance.com writes: > Subj:Re: EMC-related safety issues > Date:07/01/02 02:37:12 GMT Standard Time > From:ken.ja...@emccompliance.com (Ken Javor) > To:cherryclo...@aol.com > CC:m...@california.com, ghery.pet...@intel.com, > james.col...@usa.alcatel.com, emc-p...@majordomo.ieee.org > > Quote : "Who would have expected an unterminated HCMOS gate to be able to > emit 2W at 200MHz?" > > Not me - 2 Watts of effective radiated power implies over 2.5 V/m at 3 m! > I guess I have a hard time believing that was transmitted from an HCMOS > gate. I think a little common sense will go a long way towards retiring > some of these EMC-urban legends. > > on 1/6/02 10:40 AM, cherryclo...@aol.com at cherryclo...@aol.com wrote: > > >> A.2) A portable computing device used in an automatic change machine on >> board transport was tested to be fully compliant with EN 55022 (approx = >> CISPR 22). >> I helped the manufacturer investigate complaints of interference and >> discovered that sub-fitted variant, which had not been tested for EMC >> compliance, left an HCMOS inverter IC with an unterminated inverter - >> which promptly decided to self-oscillate at 200MHz. (Many manufacturers of >> products with a number of build variants only test the fully-loaded one >> for EMCD compliance and assume the others are at least as good.) >> >> The very interesting thing about this example is that the power-ground >> structure of the PCB made a beautifully tuned antenna and resonant circuit >> at 200MHz, so although the inverter was hard-switching and did not run >> hot, the only emissions were at the 200MHz fundamental - no harmonics were >> emitted at all. >> >> Another very interesting thing is that some of the complainants had >> measured the equivalent radiated RF power from these devices as 2W. >> > Who would have expected an unterminated HCMOS gate to be able to emit 2W at > 200MHz?
Re: ISO 11452-4 Bulk Current Injection Test Requirements
Dear Ken Your comments on what you took to be my views on the EMC testing in the automotive industry came from my ITEM UPDATE 2001 article, not from anything that I had posted on emc-pstc. As a result, people reading your posting would probably not have understood why you were referring to me. As I have described to you in a personal email today, the automotive industry comments in the above article did not originate with me, but with independent automotive EMC specialists and an EC-funded research program into the application of the Automotive EMC Directive. And just for the record I am not in favour of tests that represent a massive overkill. I am in favor of always doing good engineering to minimise your employer's commercial and financial risks - something that I think engineers can do most effectively because only they have the necessary knowledge and abilities. Regards, Keith In a message dated 10/01/02 15:37:26 GMT Standard Time, ken.ja...@emccompliance.com writes: > Subj:Re: ISO 11452-4 Bulk Current Injection Test Requirements > Date:10/01/02 15:37:26 GMT Standard Time > From:ken.ja...@emccompliance.com (Ken Javor) > To:cherryclo...@aol.com > CC:emc-p...@majordomo.ieee.org > > Keith, > > I thought of you because of previous statements that the automotive > industry wasn't testing hard enough and this seemed to me a counter-example > of massive unjustified overkill. My apologies, in the future I will only > respond to direct postings. > > Ken Javor > > on 1/10/02 8:52 AM, cherryclo...@aol.com at cherryclo...@aol.com wrote: > > >> Dear Ken >> I have no problem with "The unalterable physics of field-to-wire >> coupling". >> But I am concerned to ensure that basic physics is correctly applied in >> engineering issues. >> >> Can I please ask you to place any criticisms of me in the threads I am >> contributing to, or send them directly to me, not hide them away where I >> might not see them. >> >> (I hope to be able to get around to reading the week's contributions on >> the EMC and safety threads this weekend.) >> >> Regards, Keith Armstrong >
Re: Required separation between item with 3V/m radiated immunity and Class A ...
Dear Peter Sorry to be so late replying. One cannot in general predict the fields very close to an item of equipment from the fields measured at 10 metres. But maybe in your particular case you might be able to have some confidence in the calculation you used, especially since you don't intend to put the items any closet than 1 metre. Take a look at the useful Appendix C in Tim WIlliam's book "EMC for Product Designers" (Third edition, Newnes 2001, ISBN 0-7506-4930-5). On page 329 and 330 you'll see the full set of field equations for the emissions from a small current element. All networks of real conductors can have their emissions predicted from these equations, if you have enough computing power and enough time. As you will see, there are terms in each of the expressions for the emissions of electric and magnetic fields which relating the reciprocals of r, r squared, and r cubed, r being the distance from the tiny element. When we measure at 10 meters we generally only measure the "reciprocal of r" terms, because all the others have decayed away to nothing (or very little, anyway). Mostly, this is common-mode noise. The "reciprocal of r squared" and "reciprocal of r cubed" terms are more usually associated with differential mode emissions and with induction - both magnetic and capacitive coupling. The point at which the "reciprocal of r" terms start to dominate over the others is about one-sixth of a wavelength, so it is frequency dependant. The region where the 1/r terms dominates is known as the far field, and where the other terms dominate is called the near field. Generally speaking, the near field effects tend to increase the coupled levels of interfering signals into the victim circuit, although phase cancellation can and does occur in any real (and therefore complex) product with reflecting surfaces nearby. At 30MHz, the near-field far-field boundary is about 1.5 metres, so one might expect to get anomalous results by simply factoring the 10 metre measurement by the ratio of the distances when one gets closer in than 1.5 metres. If you are not going to place the items any closer than 1 meter, I reckon you can use the simple 'ratio of the distances' multiplier with reasonable accuracy above 50MHz. But there is no way to predict the near field intensity from the far field measurements, unless you measure the amplitude and the phase of the emissions over the surface of a sphere, and know the radiating structure of the product, and once again have a large and powerful computer and lots of time. Regards, Keith Armstrong > on 1/9/02 11:18 PM, peter.pou...@invensys.com at peter.pou...@invensys.com > wrote: > > > > > Hi Folks. > > > > At the moment I'm examining as a generic case, the potential for > > interference with Item A (tested to comply with 3V/m radiated immunity) > > caused by Item B (tested to comply with FCC or EN Class A [industrial] > > emissions). > > > > Using simple inverse distance ( E2 = E1 x d1/d2 ) extrapolation (assuming > > dominant interfering frequencies will be in the far field), I come up with > > a required separation distance of approximately 75cm to ensure the 3V/m > > immunity limit of Item A isn't exceeded by the 47dBuV/m emissions from > Item > > B. > > > > Based on this, I'd expect then the risk for EMC problems should be > > relatively low provided: > > 1. A minimum separation of 1m was used between Items A & B; > > 2. No direct interconnection of A to B via cables; > > 3. Use of a mains filter and/or separate power supply sources for A & B; > > 4. The nature of Item B is such that no significant low (eg.power) > > frequency magnetic fields are emitted; > > > > Does anyone have any experience to suggest that the minimum separation of > > 1m under theses conditions would not be adequate? > > > > Thanks, > > > > Peter Poulos > > Design Engineer > > Foxboro Transportation > > (Invensys Rail Systems Australia) >
RE: EN 50141 and EN 61000-4-6
dear John, If I would not advocate testing I would be a bad entrepreneur/ If I would recommend clearly unnecessary testing I would loose customers. The same is true for dentists curing your dents. Did YOU actually check every hole in your teeth really existed ? Or did you never go to the dentist because no authority demands it. ;<)) It is the difference between good and bad test houses to help selecting test suites for unknowing customers (!??!) that other otherwise choose for short time gains and long time losses. And, as you should know, testing costs are important for very small companies only. Costs for EMC serial production etc. are neglect able if designed in, from the start. The gain from compliant equipment in terms of quality, product life time and need for service can easily be much higher then all testing suites I can imagine. And there is much more to test than only EMC ! Regards, Gert Gremmen, (Ing) ce-test, qualified testing === Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ === >>-Original Message- >>From: owner-emc-p...@majordomo.ieee.org >>[mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of John Woodgate >>Sent: Sunday, January 13, 2002 2:29 PM >>To: emc-p...@majordomo.ieee.org >>Subject: Re: EN 50141 and EN 61000-4-6 >> >> >> >>I read in !emc-pstc that CE-test - Ing. Gert Gremmen - ce-marking and >>more... wrote (in >t...@cetest.nl>) about 'EN 50141 and EN 61000-4-6', on Sun, 13 Jan 2002: >> >>>As a member of the Dutch Committee EMC 2 I emphasize >>>these topics at every occurrence of revision or >>>amendment of these standards. >>> >> >>Good, but you are no doubt aware that many complain but few take the >>effective action that you do. >> >>>However, using the NB route >> >>NB route? >> >>>a due diligence approach >>>can be made, keeping both our customers and the >>>spectrum authorities happy. >> >>You will also, I feel sure, be aware of the difficulties here. How do >>you know how far beyond the requirements of the standards you need to >>go, to make the spectrum-management authorities happy, but not >>delirious, at your customer's expense? How can your customer reconcile >>your recommendations for 'going the extra kilometre' with the fact that >>you gain financially if your recommendation is accepted? >> >>These matters are, of course, only of concern to conscientious test- >>house managers like yourself. Less responsible managers don't worry >>about them at all. >> >>>After all, if the milking machine was tested using the >>>clamp only, and it CAUSES interference, the authorities >>>DO have all rights to demand additional measures to be taken. >> >>Yes, IF it causes interference. I wonder how likely that is. >> >>>As ce-test works in the interest of our customers we >>>decide with them that verification of those possible >>>interference must be taken into account. >> >>It is not in *your* interest to carry out extra testing? >>> >>>That's in accordance with the philosophy of the EMC-directive >>>also: requiring one to comply with the essential requirements, >>>allowing to use harmonized standards as a convenient way >>>to obtain the presumption of compliance only. >> >>Yes, many test-houses that advocate extra testing use the same argument. >>-- >>Regards, John Woodgate, OOO - Own Opinions Only. >>http://www.jmwa.demon.co.uk >>After swimming across the Hellespont, I felt like a Hero. >> >>--- >>This message is from the IEEE EMC Society Product Safety >>Technical Committee emc-pstc discussion list. >> >>Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ >> >>To cancel your subscription, send mail to: >> majord...@ieee.org >>with the single line: >> unsubscribe emc-pstc >> >>For help, send mail to the list administrators: >> Michael Garretson:pstc_ad...@garretson.org >> Dave Healddavehe...@mediaone.net >> >>For policy questions, send mail to: >> Richard Nute: ri...@ieee.org >> Jim Bacher: j.bac...@ieee.org >> >>All emc-pstc postings are archived and searchable on the web at: >>No longer online until our new server is brought online and >>the old messages are imported into the new server. >> >><>
Re: use of spirit/alcohol
I read in !emc-pstc that Kim Boll Jensen wrote
(in <3c42adb1.bb783...@post7.tele.dk>) about 'use of spirit/alcohol', on
Mon, 14 Jan 2002:
>We want to use 80% spirit/alcohol in a cooling liquid on a
>grinding/polishing machine for laboratory use under UL 3101-1 and
>EN61010-1.
It seems a very strange choice for a coolant. Can't you use a solution
of ethylene glycol, as in cars? That clearly doesn't have combustion
problems.
>
>But by a quick look in the standard Table 3, it will require that the
>spirit shall be kept at a temperature of -13 deg C
Do you really mean that, or 'less than 13 C'?
>and no vapour may
>enter the machine, since the fire point
'Flash point', I suspect
>is 12 deg. C as far as we can
>find.
>
>Have anyone some experience with spirit and know how to handle it ?
The behaviour with temperature of ethanol/water mixtures is well-
documented, of course. AIUI, for ethanol concentrations below about 75%
('constant boiling mixture') the vapour is not pure ethanol but a
hydrate containing 75% ethanol. I *suspect* that the flash point of the
hydrate is well above 12 C. If that is correct, then you might solve
your problem by using an ethanol concentration below that of the
constant-boiling mixture.
But I still think you could find a better coolant that would be quite
safe from combustion.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
After swimming across the Hellespont, I felt like a Hero.
---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.
Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/
To cancel your subscription, send mail to:
majord...@ieee.org
with the single line:
unsubscribe emc-pstc
For help, send mail to the list administrators:
Michael Garretson:pstc_ad...@garretson.org
Dave Healddavehe...@mediaone.net
For policy questions, send mail to:
Richard Nute: ri...@ieee.org
Jim Bacher: j.bac...@ieee.org
All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.
Re: EN 50141 and EN 61000-4-6
I read in !emc-pstc that Chris Chileshe
wrote (in <01c19cdd.70365940.chris.chile...@ultronics.co.uk>) about 'EN
50141 and EN 61000-4-6', on Mon, 14 Jan 2002:
>John, I found reference to a draft IEC801-5 and it appears it is the surge
>immunity,
>now IEC/EN 61000-4-5. Just so that I know where you're coming from, are you
>saying
>the reference (number) is completely wrong or that the draft never got to
>see the light
>of the day and should have never been called up?
I read your questions carefully, and decided that it's impossible to
answer them unambiguously. Won't you never fail to confirm your denial
that you are not a barrister adept at totally confusing juries, by any
chance? (;-)
Instead of trying to answer in cursive text, I'm making three
statements:
1. The reference is 'completely wrong' in the sense that no standard
exists with that reference.
2. The draft was never *carried through to publication*. However, a
product committee that considered that the surge test should be applied
to the product in question had very little option but to make a
qualified reference ('To be published' or similar words) to what was
*expected* to be the relevant Basic standard. What SHOULD have happened
was that a Corrigendum should have been issued when IEC61000-4-5 was
published.
3. There are important differences between IEC61000-4-5 and the last
draft of IEC801-5.
I hope that is clear.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
After swimming across the Hellespont, I felt like a Hero.
---
This message is from the IEEE EMC Society Product Safety
Technical Committee emc-pstc discussion list.
Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/
To cancel your subscription, send mail to:
majord...@ieee.org
with the single line:
unsubscribe emc-pstc
For help, send mail to the list administrators:
Michael Garretson:pstc_ad...@garretson.org
Dave Healddavehe...@mediaone.net
For policy questions, send mail to:
Richard Nute: ri...@ieee.org
Jim Bacher: j.bac...@ieee.org
All emc-pstc postings are archived and searchable on the web at:
No longer online until our new server is brought online and the old
messages are imported into the new server.
use of spirit/alcohol
Hi all We want to use 80% spirit/alcohol in a cooling liquid on a grinding/polishing machine for laboratory use under UL 3101-1 and EN61010-1. But by a quick look in the standard Table 3, it will require that the spirit shall be kept at a temperature of -13 deg C and no vapour may enter the machine, since the fire point is 12 deg. C as far as we can find. Have anyone some experience with spirit and know how to handle it ? Best regards, Kim Boll Jensen <>
RE: EN 50141 and EN 61000-4-6
>> At least one standard calls up IEC801-5, which simply does not exist. John, I found reference to a draft IEC801-5 and it appears it is the surge immunity, now IEC/EN 61000-4-5. Just so that I know where you're coming from, are you saying the reference (number) is completely wrong or that the draft never got to see the light of the day and should have never been called up? Regards - Chris Chileshe -Original Message- From: John Woodgate [SMTP:j...@jmwa.demon.co.uk] Sent: Saturday, January 12, 2002 8:14 AM To: emc-p...@majordomo.ieee.org Subject:Re: EN 50141 and EN 61000-4-6 I read in !emc-pstc that Mavis, Robert wrote (in ) about 'EN 50141 and EN 61000-4-6', on Fri, 11 Jan 2002: >Even though the ENV is a pre-standard, if a Product Family Standard calls it >out you must test to it. Am I not correct. AFAIK, the position is far from clear. The ENVs have been described as 'superseded' by ENs in the 61000-4 series, but do not seem to have been 'withdrawn'. Nevertheless, much of their content is now seriously out- of-date. It can just as well be argued that you must use the EN instead, because it is a 'better' standard, i.e. more certainly ensures that the 'essential requirements' are met. >Case in point, EN 50130-4 Product Family Standard for Alarm Systems calls >out specifically ENV 50141 not EN 61000-4-6. I know: see my other post saying that I am taking this up through BSI to get a general clarification from CENELEC. At least one standard calls up IEC801-5, which simply does not exist. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. This e-mail has been scanned for all viruses by Star Internet. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk This e-mail has been scanned for all viruses by Star Internet. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
EU Consultation on New Approach Directives
Hi All If you are interested in finding out more about what should be a far reaching consultation we have provided links on our home page. www.compliance-club.com We have also posted the latest Issue of the EMC Compliance Journal. Don't miss the first of a new series the John Woodgate Column. Cheers Alan E Hutley EMC Compliance Journal
EN61558 SERIES REPORT FORMS
Dear Colleagues: We have a client requiring Pretesting of transformer according to EN60558. Where can I obtain REPORT FORMS OF EN61558 SERIES STANDARD FREELY? Thanks in advance Best Regards Xing weibing 2002-01-14
RE: Basic Test Standards: old vs. new - which one?
The new Cenelec guide: CLC G 25 - Guide on the Use of Standards for the Implementation of the EMC Directive, explains the rules with regard to, as name implies, Cenelec std's and EU. Can be purchased through Cenelec web page or from any EU national std's organisation. regards, Ari Honkala > -Original Message- > From: ext John Woodgate [mailto:j...@jmwa.demon.co.uk] > Sent: 14 January, 2002 00:01 > To: emc-p...@majordomo.ieee.org > Subject: Re: Basic Test Standards: old vs. new - which one? > > > > I read in !emc-pstc that Kim Boll Jensen wrote > (in <3c41f2af.f33a6...@post7.tele.dk>) about 'Basic Test > Standards: old > vs. new - which one?', on Sun, 13 Jan 2002: > >Hi > > > >I find this discussion very interesting. > > > >The danish standardization body have the interpretation that > if a standard > >refere to another standard by number and > >year (ex. EN 61000-x-y:1996) you will have to use this > standard and not any new > >version, > > That is correct: dated references refer to that specific > edition, which > it is possible to use unless it's IEC801-5, which does not exist. > However, while it is POSSIBLE to use an old edition, it may indeed be > unwise or positively disadvantageous: some old editions are 'old' > because they are ambiguous or too stringent or don't give repeatable > results, or any permutation of all three. > > > but they recommend that you > >don't use standards which have been outdated. > > Dated references are being eliminated from ENs (so you have to use the > latest valid edition), which is OK if they refer to others > ENs, undated, > because all ENs have a specific 'dow' which indicates when they become > mandatorily valid. But IT DOESN'T WORK for references to IEC or other > standards that DON'T have a specific 'validity' date. It seems that > CENELEC BT might just conceivably have missed this point, so > representations are (I hope) being made. > > > >They told me that there wasn't any official interpretation > within EU, so before > >we gets too many questions like this I > >hope that we can get an official statement. > > > This is certainly NOT so. The rules about references to other > standards > are in Part 3 of the CENELEC Internal Regulations, although whether it > yet includes the ruling about undated references, I am not sure. > -- > Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
