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 <ken.ja...@emccompliance.com> wrote: > * This message originated outside of DISH and was sent by: > ken.ja...@emccompliance.com <ken.ja...@emccompliance.com> * > ------------------------------ > > 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 <bkundew...@gmail.com> > *Reply-To: *Brian Kunde <bkundew...@gmail.com> > *Date: *Tuesday, July 11, 2023 at 9:31 AM > *To: *<EMC-PSTC@LISTSERV.IEEE.ORG> > *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 <bdew...@ix.netcom.com> 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. To post a message to the list, send your e-mail to < > emc-p...@ieee.org> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > <http://www.ieee-pses.org/emc-pstc.html> > > Website: http://www.ieee-pses.org/ > <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 > <http://www.ieee-pses.org/listrules.html> > > For help, send mail to the list administrators: > Mike Cantwell <mcantw...@ieee.org> > > For policy questions, send mail to: > Jim Bacher <j.bac...@ieee.org> > David Heald <dhe...@gmail.com> > ------------------------------ > > To unsubscribe from the EMC-PSTC list, click the following link: > https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1 > <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 < > emc-p...@ieee.org> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > <http://www.ieee-pses.org/emc-pstc.html> > > Website: http://www.ieee-pses.org/ > <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 > <http://www.ieee-pses.org/listrules.html> > > For help, send mail to the list administrators: > Mike Cantwell <mcantw...@ieee.org> > > For policy questions, send mail to: > Jim Bacher <j.bac...@ieee.org> > David Heald <dhe...@gmail.com> > ------------------------------ > > To unsubscribe from the EMC-PSTC list, click the following link: > https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1 > <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 < > emc-p...@ieee.org> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > <http://www.ieee-pses.org/emc-pstc.html> > > Website: http://www.ieee-pses.org/ > <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 > <http://www.ieee-pses.org/listrules.html> > > For help, send mail to the list administrators: > Mike Cantwell <mcantw...@ieee.org> > > For policy questions, send mail to: > Jim Bacher <j.bac...@ieee.org> > David Heald <dhe...@gmail.com> > ------------------------------ > > To unsubscribe from the EMC-PSTC list, click the following link: > https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1 > <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 < > emc-p...@ieee.org> > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > <http://www.ieee-pses.org/emc-pstc.html> > > Website: http://www.ieee-pses.org/ > <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 > <http://www.ieee-pses.org/listrules.html> > > For help, send mail to the list administrators: > Mike Cantwell <mcantw...@ieee.org> > > For policy questions, send mail to: > Jim Bacher <j.bac...@ieee.org> > David Heald <dhe...@gmail.com> > ------------------------------ > > To unsubscribe from the EMC-PSTC list, click the following link: > https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1 > <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 ) charles.gra...@dish.com (e2) chasgra...@gmail.com - ---------------------------------------------------------------- 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 <emc-p...@ieee.org> 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) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> _________________________________________________ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1
