what year did measurement uncertainty become a required component of lab accreditation?
was there massive radio interference at homes and in offices that suddenly ceased the year after? asking for a friend. On Tue, Jul 11, 2023, 10:28 Chas Grasso <[email protected]> wrote: > When the concept of measurement uncertainty came about, the company I > worked for at the time decided that > irrespective of the technical niceties of statistics if emission exceeded > the spec but was within the stated MU, > then that was still considered a FAIL. The difficulty came when the > emission PASSED but was within the MU. > The company decided that - even if the testhouse would not declare the > pass, the product still shipped. > > In other words - life as usual. > > > > > > On Tue, Jul 11, 2023 at 9:13 AM Ken Javor <[email protected]> > wrote: > >> * This message originated outside of DISH and was sent by: >> [email protected] <[email protected]> * >> ------------------------------ >> >> Not in the commercial sector, but people try this argument all the time >> when failing a MIL-STD-461 limit by less than 3 dB, on account of the >> measurement system integrity check has to be within that margin. >> >> >> >> They *never* express such concerns when they pass within 3 dB of the >> limit, however. >> >> >> >> >> >> -- >> >> Ken Javor >> >> (256) 650-5261 >> >> >> >> *From: *Brian Kunde <[email protected]> >> *Reply-To: *Brian Kunde <[email protected]> >> *Date: *Tuesday, July 11, 2023 at 9:31 AM >> *To: *<[email protected]> >> *Subject: *Re: [PSES] FCC Part B questions >> >> >> >> If I may pile on late, keep in mind that measurement uncertainty is Plus >> or Minus (±). Years ago when I was with a previous company, we had a >> buy/sell piece of junk product that we were selling with our company's >> brand/name on it. It was audited in Sweden as part of their >> surveillance program and it failed by 2dB. The test lab said they could >> not say it FAILED because 2dB was within their measurement uncertainty, so >> we could continue to ship and sell this product in Sweden. >> >> >> >> Has anyone else ever experienced this? >> >> >> >> Thanks, >> >> The Other Brian >> >> >> >> >> >> On Sat, Jul 8, 2023 at 8:28 AM Brent DeWitt <[email protected]> >> wrote: >> >> Hi Brian. It's not entirely clear which measurement range you are asking >> about, but I'll assume conducted emissions in the range of 150 kHz to 30 >> MHz. >> >> Short answer: You can skip QP and Avg detection if the peak detection >> level is below the Avg detection limit. >> >> No margin is "required" to pass any emissions limit. Zero dB margin is >> still passing. That said, measurement uncertainty in that range is >> generally 3-4 dB, so having a passing margin greater than that gives you >> some confidence that a re-test at another time and lab will still pass. >> >> Hope that helps. >> >> respectfully, >> >> Brent DeWitt >> Milford, MA >> >> On 7/8/2023 12:38 AM, Brian Gregory wrote: >> >> >> >> Hi there, >> >> >> >> A question came up that I can't answer w/o a copy of Part 47. >> >> Does the FCC report require Quasi-Peak (QP) data, or just Avg and Peak. >> When do peak readings trigger the need to report QP? I'm pretty sure Part >> 15 has AVG and QP limits listed. >> >> >> >> Next was what sort of margin is expected in order to pass CE emissions >> requirements (CISPR 16 or 32)? Memory serves that one wants 3dB of margin, >> but memories can be imperfect! >> >> >> >> "Colorado" Brian >> 720-450-4933 >> >> - >> ---------------------------------------------------------------- >> >> This message is from the IEEE Product Safety Engineering Society emc-pstc >> discussion list. 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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.ieee-pses.org/emc-pstc.html >> >> Website: http://www.ieee-pses.org/ >> Instructions: http://www.ieee-pses.org/list.html (including how to >> unsubscribe) <http://www.ieee-pses.org/list.html> >> List rules: http://www.ieee-pses.org/listrules.html >> >> For help, send mail to the list administrators: >> Mike Cantwell <[email protected]> >> >> For policy questions, send mail to: >> Jim Bacher <[email protected]> >> David Heald <[email protected]> >> ------------------------------ >> >> To unsubscribe from the EMC-PSTC list, click the following link: >> https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1 >> >> - >> ---------------------------------------------------------------- >> >> This message is from the IEEE Product Safety Engineering Society emc-pstc >> discussion list. To post a message to the list, send your e-mail to < >> [email protected]> >> >> All emc-pstc postings are archived and searchable on the web at: >> http://www.ieee-pses.org/emc-pstc.html >> >> Website: http://www.ieee-pses.org/ >> Instructions: http://www.ieee-pses.org/list.html (including how to >> unsubscribe) <http://www.ieee-pses.org/list.html> >> List rules: http://www.ieee-pses.org/listrules.html >> >> For help, send mail to the list administrators: >> Mike Cantwell <[email protected]> >> >> For policy questions, send mail to: >> Jim Bacher <[email protected]> >> David Heald <[email protected]> >> ------------------------------ >> >> To unsubscribe from the EMC-PSTC list, click the following link: >> https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1 >> - >> ---------------------------------------------------------------- >> >> This message is from the IEEE Product Safety Engineering Society emc-pstc >> discussion list. To post a message to the list, send your e-mail to < >> [email protected]> >> >> All emc-pstc postings are archived and searchable on the web at: >> http://www.ieee-pses.org/emc-pstc.html >> >> Website: http://www.ieee-pses.org/ >> Instructions: http://www.ieee-pses.org/list.html (including how to >> unsubscribe) <http://www.ieee-pses.org/list.html> >> List rules: http://www.ieee-pses.org/listrules.html >> >> For help, send mail to the list administrators: >> Mike Cantwell <[email protected]> >> >> For policy questions, send mail to: >> Jim Bacher <[email protected]> >> David Heald <[email protected]> >> ------------------------------ >> >> To unsubscribe from the EMC-PSTC list, click the following link: >> https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1 >> > > > -- > > Charles Grasso > > Dish Technologies > > (c) 303-204-2974 > > (w) 303-706-5467 > > (h) 303-317-5530 > > (e ) [email protected] > > (e2) [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.ieee-pses.org/emc-pstc.html > > Website: http://www.ieee-pses.org/ > Instructions: http://www.ieee-pses.org/list.html (including how to > unsubscribe) <http://www.ieee-pses.org/list.html> > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Mike Cantwell <[email protected]> > > For policy questions, send mail to: > Jim Bacher <[email protected]> > David Heald <[email protected]> > ------------------------------ > > To unsubscribe from the EMC-PSTC list, click the following link: > https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1 > - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. 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