Stating a tolerance for any measurement is just good practice.
Ralph McDiarmid, AScT Compliance Engineering Group Xantrex Technology Inc. From: [email protected] [mailto:[email protected]] On Behalf Of Price, Edward Sent: Tuesday, March 31, 2009 1:54 PM To: [email protected] Subject: RE: 10cm above GRP requirement for 61000-4-6 Oops, too fast on the draw today. As Ken points out, the cable height above the ground plane in the MIL standard is 5cm, not 10cm. I must have been thinking about the distance of the EUT from the front edge of the GP. Anyway, despite my slight error of +100%, the citing about the tolerance is still valid. Now I'll go look for a place to hide & do penance. Ed Price [email protected] <blocked::mailto:[email protected]> WB6WSN NARTE Certified EMC Engineer Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 Military & Avionics EMC Is Our Specialty ________________________________ From: Ken Javor [mailto:[email protected]] Sent: Tuesday, March 31, 2009 1:44 PM To: Price, Edward Subject: Re: 10cm above GRP requirement for 61000-4-6 Hmmm, in MIL-STD-461, it is 5 cm.... Ken Javor Phone: (256) 650-5261 ________________________________ From: "Price, Edward" <[email protected]> Date: Tue, 31 Mar 2009 13:35:08 -0700 To: <[email protected]> Conversation: 10cm above GRP requirement for 61000-4-6 Subject: RE: 10cm above GRP requirement for 61000-4-6 ________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of Bob Richards Sent: Tuesday, March 31, 2009 1:10 PM To: [email protected] Subject: 10cm above GRP requirement for 61000-4-6 Fellow EMCers, 61000-4-6 says that the EUT must be 10cm above the GRP. There is no tolerance. However, anyone that has worked in a machine shop or in metrology knows that there is no such thing as "no tolerance". What would be considered an acceptable tolerance for the 10cm requirement? If an auditor says that the support for the EUT has to be exactly 10cm, "no tolerance", how can one argue with them that 1mm is not going to affect the test? The EFT standard, 61000-4-4, says 10cm +/- 1cm. Could this be used as a basis for an argument? Bob Richards, NCT Bob: FWIW, MIL-STD-461, which has been around longer than 61000 (and thus was probably the inspiration for "10 cm"), says, in Paragraph 4.3.1., "Unless otherwise stated...tolerance shall be... Distance: +/- 5%" Ed Price [email protected] <blocked::mailto:[email protected]> <mailto:[email protected]%3e> WB6WSN NARTE Certified EMC Engineer Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 Military & Avionics EMC Is Our Specialty - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]>
