RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, )
Robert, The North American paper sizes are not irrational, just dated. The engineering sizes (A through D) were originally mainly used with the contact diazo (blueprint) duplicating method. The copies are all at 1:1 ratio with the original drawing, which was hand drawn in the days before CAD. Enlarging/reducing had to be done with a very large and expensive process camera. This was usually only done to make offset printing plates for manuals. The selection of sizes was actually very rational, as all the larger sizes can be neatly folded to A size (8 1/2 X 11) with the title block showing on top. As for the U.S. Patent Office, I believe the switch to the metric paper was done at the same time the patent period was changed (along with other details) to harmonize with other nations under international patent agreements. Finally, the side issue of discussing paper sizes resulted after it was mentioned that the downloaded galvanic compatibility chart could not be printed on 8 1/2 X 11 paper. If the host based printer driver is loaded it is possible to scale printed output to any size desired. The hardware based print drivers generally do not have this ability. Scott Lacey -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of Robert Wilson Sent: Tuesday, March 05, 2002 11:47 AM To: emc-p...@majordomo.ieee.org Subject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, ) More importantly, North American paper sizes are just plain irrational. At least the metric sizes all have the same aspect ratio, so enlarging/reducing from one size to another doesn't result in a large band of unused space. Even the US Patent Office has given up on US A (8-12 x 11) or US legal (8-1/2 x 14) size, and for at least 10 years, submissions have to be made on the metric A4 size paper that most of the civilized world uses. Bob Wilson TIR Systems Ltd. Vancouver. -Original Message- From: John Shinn [mailto:john.sh...@sanmina-sci.com] Sent: March 4, 2002 4:18 PM To: 'John Woodgate'; emc-p...@majordomo.ieee.org Subject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, ) Actually, US Legal size is 8-1/2 by 14 inches. 8-1/2 by 17 inches is B-size. John Shinn, P.E. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of John Woodgate Sent: Monday, March 04, 2002 11:36 AM To: emc-p...@majordomo.ieee.org Subject: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, ) I read in !emc-pstc that david_ster...@ademco.com wrote (in 2DF7C54A75B dd311b61700508b64231002c5a...@nyhqex1.ademcohq.com) about 'Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, )', on Mon, 4 Mar 2002: It prints on legal (8-1/2 x 17) paper. That size is 'illegal' in Europe! (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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
RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, )
More importantly, North American paper sizes are just plain irrational. At least the metric sizes all have the same aspect ratio, so enlarging/reducing from one size to another doesn't result in a large band of unused space. Even the US Patent Office has given up on US A (8-12 x 11) or US legal (8-1/2 x 14) size, and for at least 10 years, submissions have to be made on the metric A4 size paper that most of the civilized world uses. Bob Wilson TIR Systems Ltd. Vancouver. -Original Message- From: John Shinn [mailto:john.sh...@sanmina-sci.com] Sent: March 4, 2002 4:18 PM To: 'John Woodgate'; emc-p...@majordomo.ieee.org Subject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, ) Actually, US Legal size is 8-1/2 by 14 inches. 8-1/2 by 17 inches is B-size. John Shinn, P.E. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of John Woodgate Sent: Monday, March 04, 2002 11:36 AM To: emc-p...@majordomo.ieee.org Subject: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, ) I read in !emc-pstc that david_ster...@ademco.com wrote (in 2DF7C54A75B dd311b61700508b64231002c5a...@nyhqex1.ademcohq.com) about 'Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, )', on Mon, 4 Mar 2002: It prints on legal (8-1/2 x 17) paper. That size is 'illegal' in Europe! (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, )
You are right, I was not yet awake. Sorry. -Original Message- From: Ron Pickard [mailto:rpick...@hypercom.com] Sent: Tuesday, March 05, 2002 7:21 AM To: john.sh...@sanmina-sci.com Cc: emc-p...@ieee.org Subject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, ) Hi John, Actually, B-size is 11 x 17 inches. Best regards, Ron Pickard rpick...@hypercom.com john.shinn@sanmina-sci. comTo: j...@jmwa.demon.co.uk, emc-p...@majordomo.ieee.org Sent by: cc: owner-emc-pstc@majordomSubject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating o.ieee.org surface s, chassis, ) 03/04/02 05:17 PM Please respond to john.shinn Actually, US Legal size is 8-1/2 by 14 inches. 8-1/2 by 17 inches is B-size. John Shinn, P.E. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of John Woodgate Sent: Monday, March 04, 2002 11:36 AM To: emc-p...@majordomo.ieee.org Subject: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, ) I read in !emc-pstc that david_ster...@ademco.com wrote (in 2DF7C54A75B dd311b61700508b64231002c5a...@nyhqex1.ademcohq.com) about 'Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, )', on Mon, 4 Mar 2002: It prints on legal (8-1/2 x 17) paper. That size is 'illegal' in Europe! (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, )
Hi John, Actually, B-size is 11 x 17 inches. Best regards, Ron Pickard rpick...@hypercom.com john.shinn@sanmina-sci. comTo: j...@jmwa.demon.co.uk, emc-p...@majordomo.ieee.org Sent by: cc: owner-emc-pstc@majordomSubject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating o.ieee.org surface s, chassis, ) 03/04/02 05:17 PM Please respond to john.shinn Actually, US Legal size is 8-1/2 by 14 inches. 8-1/2 by 17 inches is B-size. John Shinn, P.E. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of John Woodgate Sent: Monday, March 04, 2002 11:36 AM To: emc-p...@majordomo.ieee.org Subject: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, ) I read in !emc-pstc that david_ster...@ademco.com wrote (in 2DF7C54A75B dd311b61700508b64231002c5a...@nyhqex1.ademcohq.com) about 'Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, )', on Mon, 4 Mar 2002: It prints on legal (8-1/2 x 17) paper. That size is 'illegal' in Europe! (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, )
Actually, US Legal size is 8-1/2 by 14 inches. 8-1/2 by 17 inches is B-size. John Shinn, P.E. -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of John Woodgate Sent: Monday, March 04, 2002 11:36 AM To: emc-p...@majordomo.ieee.org Subject: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, ) I read in !emc-pstc that david_ster...@ademco.com wrote (in 2DF7C54A75B dd311b61700508b64231002c5a...@nyhqex1.ademcohq.com) about 'Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, )', on Mon, 4 Mar 2002: It prints on legal (8-1/2 x 17) paper. That size is 'illegal' in Europe! (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, )
I imported it from their website into MS Word. It prints on legal (8-1/2 x 17) paper. Click on any product, then click the topics in the pull-down menu. Select 'metal compatibility' David -Original Message- From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Monday, March 04, 2002 8:43 AM To: John Woodgate; emc-p...@majordomo.ieee.org Subject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, ) How can one obtain the graph? I got mine by accident. Instrument Specialties is only a six hour drive away. We have done osme business with them and they used to visit our company regularly. During one of the visits they just gave me a design guide (it's a catalog of products that also includes some tips on how to use their products). I've been told that Instrument Specialties is now Laird Technologies. Maybe you can look them up on the web? (www.instr.com still works) It would really be great if they had put their design guide online. Or maybe if you could contact them from the website; perhaps they could mail you a design guide. The potential problem here is that my copy is an old one ~1997. They may have edited the metals compatibility graph out of later editions. Best regards, Chris -Original Message- From: John Woodgate [SMTP:j...@jmwa.demon.co.uk] Sent: Friday, March 01, 2002 5:19 PM To: emc-p...@majordomo.ieee.org Subject: Re: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, ) I read in !emc-pstc that Chris Maxwell chris.maxw...@nettest.com wrote (in 83d652574e7af740873674f9fc12dbaaf7d...@utexh1w2.gnnettest.com) about 'Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, )', on Fri, 1 Mar 2002: If you're worried about galvanic corrosion. An excellent (and free) source of information is the Instrument Specialties Catalog and Design Guide.The back cover is a foldout which has a very nice color coded chart that shows metal compatibility while taking into account the environment. Their graph is easily worth a thousand words. How can one obtain it? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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/so
RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, )
How can one obtain the graph? I got mine by accident. Instrument Specialties is only a six hour drive away. We have done osme business with them and they used to visit our company regularly. During one of the visits they just gave me a design guide (it's a catalog of products that also includes some tips on how to use their products). I've been told that Instrument Specialties is now Laird Technologies. Maybe you can look them up on the web? (www.instr.com still works) It would really be great if they had put their design guide online. Or maybe if you could contact them from the website; perhaps they could mail you a design guide. The potential problem here is that my copy is an old one ~1997. They may have edited the metals compatibility graph out of later editions. Best regards, Chris -Original Message- From: John Woodgate [SMTP:j...@jmwa.demon.co.uk] Sent: Friday, March 01, 2002 5:19 PM To: emc-p...@majordomo.ieee.org Subject: Re: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, ) I read in !emc-pstc that Chris Maxwell chris.maxw...@nettest.com wrote (in 83d652574e7af740873674f9fc12dbaaf7d...@utexh1w2.gnnettest.com) about 'Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, )', on Fri, 1 Mar 2002: If you're worried about galvanic corrosion. An excellent (and free) source of information is the Instrument Specialties Catalog and Design Guide.The back cover is a foldout which has a very nice color coded chart that shows metal compatibility while taking into account the environment. Their graph is easily worth a thousand words. How can one obtain it? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, )
I read in !emc-pstc that Chris Maxwell chris.maxw...@nettest.com wrote (in 83d652574e7af740873674f9fc12dbaaf7d...@utexh1w2.gnnettest.com) about 'Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, )', on Fri, 1 Mar 2002: If you're worried about galvanic corrosion. An excellent (and free) source of information is the Instrument Specialties Catalog and Design Guide.The back cover is a foldout which has a very nice color coded chart that shows metal compatibility while taking into account the environment. Their graph is easily worth a thousand words. How can one obtain it? -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surface s, chassis, )
Chris, Instrument Specialties is now Laird Technologies for those who do not yet know. Josh -Original Message- From: Chris Maxwell [mailto:chris.maxw...@nettest.com] Sent: Friday, March 01, 2002 11:46 AM To: Robert Wilson; emc-p...@majordomo.ieee.org Subject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, ) If you're worried about galvanic corrosion. An excellent (and free) source of information is the Instrument Specialties Catalog and Design Guide.The back cover is a foldout which has a very nice color coded chart that shows metal compatibility while taking into account the environment. Their graph is easily worth a thousand words. Chris -Original Message- From: Robert Wilson [SMTP:robert_wil...@tirsys.com] Sent: Friday, March 01, 2002 12:20 PM To: emc-p...@majordomo.ieee.org Subject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, ) One must take care to separate fact from opinions. Mixing metals as you mention is NOT necessarily a sure way to promote corrosion. Yes, steel against aluminum us not good practice since they are far enough apart on the electromotive series that they will act as a local battery (in the presence of an electrolyte such as salt water), and the aluminum will corrode. Another bad pair is aluminum against copper alloys. But in a dry environment, no problem can occur since no moisture is present. Galvanic corrosion without the presence of an electrolyte is impossible. Other metal combinations are also problematic such as aluminum against zinc plated or galvanized steel (or zinc plated anything). Cadmium plated steel against aluminum is generally considered an acceptable combination, as is 300-series stainless steel against most metals. 300-series stainless (especially type 316) is considered relatively passive. One must simply choose the metal pairs carefully, taking into account the environment, and if necessary making sure they are sufficiently close in voltage potential to each other on the electromotive scale. Bob Wilson TIR Systems Ltd. Vancouver. -Original Message- From: Wan Juang Foo [mailto:f...@np.edu.sg] Sent: February 28, 2002 11:12 PM To: emc-p...@majordomo.ieee.org Subject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, ) David, You mention that you have a Steel and Aluminium to content with. My opinion about mixing metal parts in an assembly (chassis) is a sure way of promoting corrosion, especially if the installation is in a humid environment. If you want the chassis to be a reliable electrostatic shield do not have panels that are made with different metal bolted to the 'frame' or chassis. Under some codes this is a 'No Go' area. BTW, I assume that you must be working with a small box, otherwise you would need much more than a 'rubber eraser' to clean the mating surfaces. All equipment metalwork should be electrically bonded in a manner which does not rely on 'hopeful' electrical conduction through anti-corrosive treatment like anodised aluminium and paint. Careful attention to the assembly process will weed out things like ball-bearings races, nylon runners and coasters, or other insulating materials. Conduction through painted panels should not be dependent on the gripping action of star washers. The design should be such that no currents flows in any part of the metal work. The objective is to ensure that any part of the metalwork can be relied upon as an effective electrostatic screen and not the reverse, a radiator. Tim Foo --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@mediaone.net For policy questions, send mail to: Richard
RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, )
If you're worried about galvanic corrosion. An excellent (and free) source of information is the Instrument Specialties Catalog and Design Guide.The back cover is a foldout which has a very nice color coded chart that shows metal compatibility while taking into account the environment. Their graph is easily worth a thousand words. Chris -Original Message- From: Robert Wilson [SMTP:robert_wil...@tirsys.com] Sent: Friday, March 01, 2002 12:20 PM To: emc-p...@majordomo.ieee.org Subject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, ) One must take care to separate fact from opinions. Mixing metals as you mention is NOT necessarily a sure way to promote corrosion. Yes, steel against aluminum us not good practice since they are far enough apart on the electromotive series that they will act as a local battery (in the presence of an electrolyte such as salt water), and the aluminum will corrode. Another bad pair is aluminum against copper alloys. But in a dry environment, no problem can occur since no moisture is present. Galvanic corrosion without the presence of an electrolyte is impossible. Other metal combinations are also problematic such as aluminum against zinc plated or galvanized steel (or zinc plated anything). Cadmium plated steel against aluminum is generally considered an acceptable combination, as is 300-series stainless steel against most metals. 300-series stainless (especially type 316) is considered relatively passive. One must simply choose the metal pairs carefully, taking into account the environment, and if necessary making sure they are sufficiently close in voltage potential to each other on the electromotive scale. Bob Wilson TIR Systems Ltd. Vancouver. -Original Message- From: Wan Juang Foo [mailto:f...@np.edu.sg] Sent: February 28, 2002 11:12 PM To: emc-p...@majordomo.ieee.org Subject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, ) David, You mention that you have a Steel and Aluminium to content with. My opinion about mixing metal parts in an assembly (chassis) is a sure way of promoting corrosion, especially if the installation is in a humid environment. If you want the chassis to be a reliable electrostatic shield do not have panels that are made with different metal bolted to the 'frame' or chassis. Under some codes this is a 'No Go' area. BTW, I assume that you must be working with a small box, otherwise you would need much more than a 'rubber eraser' to clean the mating surfaces. All equipment metalwork should be electrically bonded in a manner which does not rely on 'hopeful' electrical conduction through anti-corrosive treatment like anodised aluminium and paint. Careful attention to the assembly process will weed out things like ball-bearings races, nylon runners and coasters, or other insulating materials. Conduction through painted panels should not be dependent on the gripping action of star washers. The design should be such that no currents flows in any part of the metal work. The objective is to ensure that any part of the metalwork can be relied upon as an effective electrostatic screen and not the reverse, a radiator. Tim Foo --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, )
One must take care to separate fact from opinions. Mixing metals as you mention is NOT necessarily a sure way to promote corrosion. Yes, steel against aluminum us not good practice since they are far enough apart on the electromotive series that they will act as a local battery (in the presence of an electrolyte such as salt water), and the aluminum will corrode. Another bad pair is aluminum against copper alloys. But in a dry environment, no problem can occur since no moisture is present. Galvanic corrosion without the presence of an electrolyte is impossible. Other metal combinations are also problematic such as aluminum against zinc plated or galvanized steel (or zinc plated anything). Cadmium plated steel against aluminum is generally considered an acceptable combination, as is 300-series stainless steel against most metals. 300-series stainless (especially type 316) is considered relatively passive. One must simply choose the metal pairs carefully, taking into account the environment, and if necessary making sure they are sufficiently close in voltage potential to each other on the electromotive scale. Bob Wilson TIR Systems Ltd. Vancouver. -Original Message- From: Wan Juang Foo [mailto:f...@np.edu.sg] Sent: February 28, 2002 11:12 PM To: emc-p...@majordomo.ieee.org Subject: RE: Pencil erasers for pre-EMI cleaning? (cleaning mating surfaces, chassis, ) David, You mention that you have a Steel and Aluminium to content with. My opinion about mixing metal parts in an assembly (chassis) is a sure way of promoting corrosion, especially if the installation is in a humid environment. If you want the chassis to be a reliable electrostatic shield do not have panels that are made with different metal bolted to the 'frame' or chassis. Under some codes this is a 'No Go' area. BTW, I assume that you must be working with a small box, otherwise you would need much more than a 'rubber eraser' to clean the mating surfaces. All equipment metalwork should be electrically bonded in a manner which does not rely on 'hopeful' electrical conduction through anti-corrosive treatment like anodised aluminium and paint. Careful attention to the assembly process will weed out things like ball-bearings races, nylon runners and coasters, or other insulating materials. Conduction through painted panels should not be dependent on the gripping action of star washers. The design should be such that no currents flows in any part of the metal work. The objective is to ensure that any part of the metalwork can be relied upon as an effective electrostatic screen and not the reverse, a radiator. Tim Foo --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: Pencil erasers for pre-EMI cleaning?
this particular sample has been thoroughly abused in environmental testing (including several unintentional unfortunate CONDENSING temp humidity runs - ever look into a chamber and see what looks like your product sitting in a cloud? Not fun). Months and tests later, the dirt or grime is easily visible on a lot of the mating surfaces and is not at all present on new samples. My first EMC job out of the Army (in 83) was in doing audit testing of production equipment. I noticed early on that it tested better if we checked AFTER the shake test. This was probably due to the fact that the non-conducting stuff had all been worn off of mating surfaces by vibration. Cortland --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: Pencil erasers for pre-EMI cleaning?
Thanks everyone for your input. And let me put everyone's fears at ease by saying that this particular sample has been thoroughly abused in environmental testing (including several unintentional unfortunate CONDENSING temp humidity runs - ever look into a chamber and see what looks like your product sitting in a cloud? Not fun). Months and tests later, the dirt or grime is easily visible on a lot of the mating surfaces and is not at all present on new samples. Unfortunately, an entire new sample costs over $1M, so let's just say I'm not getting a new one. And for the steel / Al concerns, the different metals are in different sections so mating is not an issue, just the risk of corrosion if I remove the protective coatings. So, I am simply trying to restore the sample to its original condition (or as close as I can get to it). I would never advocate sprucing up a test sample just to pass a test. And it turns out we use nickel plate which should be quite durable. Again, any comments from experience would be welcome, but my guys say that I shouldn't have problems. Thanks again! Dave Heald David Heald wrote: All, I'm preparing for an emissions test and I had started cleaning some of my chassis mating surfaces with a pen/pencil eraser then alcohol to ensure the surface to surface contact was good. A friend then told me that using an eraser would also remove the anti-corrosive coating that was on the metal (Thanks Paul!). So I would end up with a very short term benefit, then rust. What I am trying to determine is if maybe light rubbing with a pencil eraser might only remove surface contaminants and leave the metal and coatings intact. (the pencil eraser is much less abrasive than the pen side) So the real question is... Does anyone have direct good or bad experience with the aftereffects of using a pencil eraser to clean mating edges (card faceplates in a telco box for example)? I have both steel and aluminum surfaces to worry about so info for either type is welcome. (and don't worry the different metal types are not adjacent). Any feedback would be greatly appreciated as the system is really dirty right now. Thanks and Best Regards, Dave Heald --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Pencil erasers for pre-EMI cleaning?
Hi Dave, Those were the days. Computer not working, pull out all the cards and take an eraser to the gold fingers. Put it back together and Voila! everything works. In a perfect world, my opinion coincides with those previously expressed. We should be testing with pristine equipment, as a customer can expect to receive. This means items direct from the manufacturing process. Perhaps many of the esteemed members of this group are in positions that afford them these resources. My personal experience has been one of receiving the latest prototype that has been passed around through many hands and has little cosmetic resemblance to that shipping to customers. In these situations, I believe that it is of mandatory importance, if your equipment is a card slot type or has removable parts/panels, to try to return the item to as pristine a condition as you can prior to test. There is just as much probability of connection debris preventing a ground loop that would have increased emissions/susceptibility as there is for it reducing them. To the specific question of the eraser: I heard a couple of eons ago that pencil erasures leave a contaminating residue and they should not be used, especially on gold flash, leading me to seek alternatives to the Good 'ol Days mentioned above. I use contact cleaner made for noble metals on edge fingers and frequently use a 50:50 mixture of denatured alcohol and distilled water to clean gasketing materials to remove oil and dust deposited by handling. One other design type note: If you are using steel, think about zinc plating. It is well worth the money. Your finish should not be so fragile if expected to stand up to normal wear and tear. Have a Great Day! Dave -Original Message- From: David Heald [mailto:davehe...@mediaone.net] Sent: Thursday, February 28, 2002 11:44 AM To: emc-p...@majordomo.ieee.org Subject: Pencil erasers for pre-EMI cleaning? All, I'm preparing for an emissions test and I had started cleaning some of my chassis mating surfaces with a pen/pencil eraser then alcohol to ensure the surface to surface contact was good. A friend then told me that using an eraser would also remove the anti-corrosive coating that was on the metal (Thanks Paul!). So I would end up with a very short term benefit, then rust. What I am trying to determine is if maybe light rubbing with a pencil eraser might only remove surface contaminants and leave the metal and coatings intact. (the pencil eraser is much less abrasive than the pen side) So the real question is... Does anyone have direct good or bad experience with the aftereffects of using a pencil eraser to clean mating edges (card faceplates in a telco box for example)? I have both steel and aluminum surfaces to worry about so info for either type is welcome. (and don't worry the different metal types are not adjacent). Any feedback would be greatly appreciated as the system is really dirty right now. Thanks and Best Regards, Dave Heald --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Pencil erasers for pre-EMI cleaning?
I agree if this was the actual EUT under test, but if it is a peripheral that gets used lots, or if its a PC chassis for example I would clean the surfaces at any point I got nervous about the performance. One of the reasons that it is difficult to find a PC that meets the emissions limits is that after shipping or opening and closing the fool things a number of times the mating surfaces get crunged up (technically speaking) and build up a certain amount of resistance. I can't afford new peripherals every try so I just get these surfaces back to as built condition. If you have to do this on the EUT it should only be done if you find it a problem because it caused a failure. Then as suggested many times prior you have to go back to the design guys and tell them they have to fix it before you can certify it. I haven't had had any problems with erasers and good electrical cleaners like you can find in the lab. I would stay well short of sandpaper or anything abrasive because it can go through whatever plating is being used for corrosion protection. The problem only gets worse after that. So will many cleanings with the eraser. Gary -Original Message- From: John Juhasz [mailto:jjuh...@fiberoptions.com] Sent: Thursday, February 28, 2002 1:08 PM To: 'David Heald'; emc-p...@majordomo.ieee.org Subject: RE: Pencil erasers for pre-EMI cleaning? I'm sure there are products on the market just for this purpose. But I would be concerned about my design if pass/fail depended upon how clean the mating surfaces are. A component substitution or some other ECO to the product down the line could put the product over the limit. Refer to the thread on test margins. John Juhasz Fiber Options Bohemia, NY -Original Message- From: David Heald [mailto:davehe...@mediaone.net] Sent: Thursday, February 28, 2002 2:44 PM To: emc-p...@majordomo.ieee.org Subject: Pencil erasers for pre-EMI cleaning? All, I'm preparing for an emissions test and I had started cleaning some of my chassis mating surfaces with a pen/pencil eraser then alcohol to ensure the surface to surface contact was good. A friend then told me that using an eraser would also remove the anti-corrosive coating that was on the metal (Thanks Paul!). So I would end up with a very short term benefit, then rust. What I am trying to determine is if maybe light rubbing with a pencil eraser might only remove surface contaminants and leave the metal and coatings intact. (the pencil eraser is much less abrasive than the pen side) So the real question is... Does anyone have direct good or bad experience with the aftereffects of using a pencil eraser to clean mating edges (card faceplates in a telco box for example)? I have both steel and aluminum surfaces to worry about so info for either type is welcome. (and don't worry the different metal types are not adjacent). Any feedback would be greatly appreciated as the system is really dirty right now. Thanks and Best Regards, Dave Heald --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p
RE: Pencil erasers for pre-EMI cleaning?
David, Forget the pencil eraser. This is the same deal as using one to clean battery contacts. Works great - for a short time. Look on the web for Caig Laboratories, Inc. they make a series of chemicals that are meant to deoxidize metal contacts. I've used their DeoxIT D5 for years. I call it gremlin spray because it gets rid of pesky intermittent connections. Scott Lacey -Original Message- From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org]On Behalf Of David Heald Sent: Thursday, February 28, 2002 2:44 PM To: emc-p...@majordomo.ieee.org Subject: Pencil erasers for pre-EMI cleaning? All, I'm preparing for an emissions test and I had started cleaning some of my chassis mating surfaces with a pen/pencil eraser then alcohol to ensure the surface to surface contact was good. A friend then told me that using an eraser would also remove the anti-corrosive coating that was on the metal (Thanks Paul!). So I would end up with a very short term benefit, then rust. What I am trying to determine is if maybe light rubbing with a pencil eraser might only remove surface contaminants and leave the metal and coatings intact. (the pencil eraser is much less abrasive than the pen side) So the real question is... Does anyone have direct good or bad experience with the aftereffects of using a pencil eraser to clean mating edges (card faceplates in a telco box for example)? I have both steel and aluminum surfaces to worry about so info for either type is welcome. (and don't worry the different metal types are not adjacent). Any feedback would be greatly appreciated as the system is really dirty right now. Thanks and Best Regards, Dave Heald --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
RE: Pencil erasers for pre-EMI cleaning?
I'm sure there are products on the market just for this purpose. But I would be concerned about my design if pass/fail depended upon how clean the mating surfaces are. A component substitution or some other ECO to the product down the line could put the product over the limit. Refer to the thread on test margins. John Juhasz Fiber Options Bohemia, NY -Original Message- From: David Heald [mailto:davehe...@mediaone.net] Sent: Thursday, February 28, 2002 2:44 PM To: emc-p...@majordomo.ieee.org Subject: Pencil erasers for pre-EMI cleaning? All, I'm preparing for an emissions test and I had started cleaning some of my chassis mating surfaces with a pen/pencil eraser then alcohol to ensure the surface to surface contact was good. A friend then told me that using an eraser would also remove the anti-corrosive coating that was on the metal (Thanks Paul!). So I would end up with a very short term benefit, then rust. What I am trying to determine is if maybe light rubbing with a pencil eraser might only remove surface contaminants and leave the metal and coatings intact. (the pencil eraser is much less abrasive than the pen side) So the real question is... Does anyone have direct good or bad experience with the aftereffects of using a pencil eraser to clean mating edges (card faceplates in a telco box for example)? I have both steel and aluminum surfaces to worry about so info for either type is welcome. (and don't worry the different metal types are not adjacent). Any feedback would be greatly appreciated as the system is really dirty right now. Thanks and Best Regards, Dave Heald --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: Pencil erasers for pre-EMI cleaning?
David Heald wrote: I'm preparing for an emissions test and I had started cleaning some of my chassis mating surfaces with a pen/pencil eraser then alcohol to ensure the surface to surface contact was good. David, This is an ever present help in time of trouble. Don't do it. (grin) Cleaning mating surfaces will help pass a test. But it is a bad idea. The purpose of a test is to catch what fails. If there's a nonconductive film preventing contact -- and this is common! -- then you need to change the process that put it there. Or find another way to make contact in that location. You want your PRODUCTS to pass, not just your test samples. It is a great troubleshooting, tool, however. I favor a paper towel with alcohol; the silicates in the paper are rough enough, usually, and the alcohol will dissolve some of the grease. Cortland --- 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@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: http://ieeepstc.mindcruiser.com/ Click on browse and then emc-pstc mailing list
Re: Pencil erasers for pre-EMI cleaning?
I'm not trying to be antagonistic, but unless you plan to perform this procedure on all production devices - neither should you do so to the test sample(s). My 2 cents worth. Regards, Stephen At 02:43 PM 2/28/2002, you wrote: All, I'm preparing for an emissions test and I had started cleaning some of my chassis mating surfaces with a pen/pencil eraser then alcohol to ensure the surface to surface contact was good. A friend then told me that using an eraser would also remove the anti-corrosive coating that was on the metal (Thanks Paul!). So I would end up with a very short term benefit, then rust. What I am trying to determine is if maybe light rubbing with a pencil eraser might only remove surface contaminants and leave the metal and coatings intact. (the pencil eraser is much less abrasive than the pen side) So the real question is... Does anyone have direct good or bad experience with the aftereffects of using a pencil eraser to clean mating edges (card faceplates in a telco box for example)? I have both steel and aluminum surfaces to worry about so info for either type is welcome. (and don't worry the different metal types are not adjacent). Any feedback would be greatly appreciated as the system is really dirty right now.
