I'm sure those on that committee hashed through all this in agonizing detail. So this is a general comment for those, like myself, not part of that committee.
If, and I stress if, there were a need and desire to protect mobile phone use while seated at your PC, then the measurement would have to be made at a representative distance (say 1 meter). The antenna used to measure the emissions would need to look like a cell phone antenna, but we could make it a dipole to get a better pattern and a repeatable, known antenna factor. Now if the PC were a compact blob you could just use a small turntable and small mast and scale down the standard OATS measurement. But since the PC is an extended system with multiple interfaces, the outline is not circular. That means that if we try to enforce a 1 meter antenna-EUT separation, the antenna has to move towards and then away from the EUT as the EUT revolves. Another factor is that if you design to protect a -105 dBm receiver one meter from the test sample, you are in fact and practice imposing a military standard radiated emission limit. A quick look at military electronic chassis and cable shielding practices will convince you that there is a design and cost impact to doing this. Sounds like lots of fun. Just use a land line! > From: "Pettit, Ghery" <ghery.pet...@intel.com> > Date: Tue, 2 Aug 2005 09:14:12 -0700 > To: "Ken Javor" <ken.ja...@emccompliance.com>, <emc-p...@ieee.org> > Subject: RE: Request for info on CE Mark penalties > > Ken, > > You would love some of the discussions that occurred in CISPR SC I on > this very subject when we were debating setting limits above 1 GHz for > CISPR 22. Two sides - those who made your point (and argued for > adopting the existing limits provided by the FCC) and those who wanted > to protect a mobile phone used at your desk (and who wanted limits about > 7 dB lower than the FCC limits). Neither side had enough votes to > prevail, and both sides had enough votes in ensure that the other side > did not prevail. That's how we wound up with the political compromise > limits that were published last month in Amendment 1 to CISPR 22:2005. > > Ghery S. Pettit > > > -----Original Message----- > From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ken > Javor > Sent: Tuesday, August 02, 2005 9:06 AM > To: emc-p...@ieee.org > Subject: Re: Request for info on CE Mark penalties > > The obvious response here is that CISPR and FCC RE requirements are not > meant to protect a victim from a culprit at one meter separation. > Generally > they do a fine job at three meters or more. The purpose of RE limits is > not > to protect your use of your cell phone while working at your PC. It is > to > protect a radio receiver user from a culprit operated at some distance > from > the victim, and generally when the culprit is not under control of the > victim. > >> From: drcuthb...@micron.com >> Date: Tue, 2 Aug 2005 09:15:35 -0600 >> To: <ken.ja...@emccompliance.com>, <emc-p...@ieee.org> >> Subject: RE: Request for info on CE Mark penalties >> >> Today's heavy RF communications environment: >> >> Let's take the case of a cell phone having a minimum useful receive >> signal of -105 dBm and a PC that radiates a signal, in the 850 MHz > cell >> phone band, that is 37 dBuV/m @ 3 meters. The PC is legal. Let's place >> the cell phone 1 meter from the PC. The cell phone antenna has an AF > of >> 29 dB. The PC signal is -90 dBm at the cell phone receiver input. This >> can certainly bother the cell phone and cause it to change frequency. > We >> have to move the cell phone over 6 meters away before it will ignore > the >> PC. >> >> Is anyone aware of any issues with cell phones and such? I realize > these >> services have some frequency agility and perhaps that mitigates these >> issues. >> >> Dave Cuthbert >> Micron Technology >> >> -----Original Message----- >> From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ken >> Javor >> Sent: Tuesday, August 02, 2005 7:14 AM >> To: emc-p...@ieee.org >> Subject: Re: Request for info on CE Mark penalties >> >> In the USA, FCC CE and RE limits for digital equipment were first >> derived as >> described in CBEMA Report ESC5/77/29. CE limits were based on >> measurements >> of victim radio sensitivity below 30 MHz, and RE limits were based on >> EIA >> specs for radio receiver sensitivity above 30 MHz. >> >> In other words, just as Mr. Woodgate states. I saw nothing about >> margins. >> Instead, the measurement methods were chosen to provide suitable >> accuracy. >> Thus, for instance, the 30 MHz break for CE/RE measurements. 30 MHz > was >> stated to be the lowest frequency at which reasonably accurate RE >> measurements could be made at three meters. Analysis predicted that > the >> 48 >> dBuV CE limit was sufficient to protect against RE below 30 MHz. The >> limits >> were placed just as Mr. Woodgate states, to minimize EMI complaints >> under >> typical but not all conditions. The 450 kHz lower end of FCC >> measurements >> encompassed the MW AM band plus the 455 kHz IF of AM band radios. In >> Europe, the lower frequency was 150 kHz because of 150 kHz - 300 kHz > LW >> AM >> band usage. >> >> In this country we have LORAN navigation in use near the coasts, but > it >> was >> deemed economically unsound to mandate that all office equipment meet > CE >> limits to protect a few coastal radio victims. >> >>> From: rehel...@mmm.com >>> Date: Tue, 2 Aug 2005 02:49:02 -0500 >>> To: emc-p...@ieee.org >>> Subject: RE: Request for info on CE Mark penalties >>> >>> Dave, I have been trying for some time now to find out just exactly >> how >>> limits lines were derived. Can you point me to a study/report/data >> that can >>> show me (or more importantly, others here at work) just how the > limits >> were >>> derived? No one seems to be able to. >>> >>> Bob Heller >>> 3M EMC Laboratory, 76-1-01 >>> St. Paul, MN 55107-1208 >>> Tel: 651- 778-6336 >>> Fax: 651-778-6252 >>> ========================= >>> >>> >>> >>> drcuthbert@micron >>> .com >>> Sent by: To >>> emc-p...@ieee.org <john_t...@bose.com> >>> <emc-p...@ieee.org> >>> cc >>> 08/01/2005 11:53 >>> AM Subject >>> RE: Request for info on CE Mark >>> penalties >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> John, >>> >>> the consideration of penalties is a form of consequentialist ethics >> that >>> focuses on "us". A higher form (in my opinion) is to focus on the >>> consequences to "the other." In this case, the other is society. As >> you >>> know, the EMC limits are not arbitrary; they are based on the >> interference >>> potential to EM communications. So one can consider that shipping a >> product >>> that exceeds the EMC limits could potentially harm society. >>> >>> One can take this one step further and consider that a product that > is >>> under the EMC limits can still potentially harm society, but that it >> is not >>> as harmful as a product that exceeds the EMC limits. In this case we >> can >>> site rule based ethics by proclaiming that we meet the EMC rules and >>> therefore we have done all that we are required to do. These two >>> conflicting ethical positions could make for a long and interesting >>> discussion. >>> >>> Dave Cuthbert >>> Micron Technology >>> >>> >>> >>> From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Tyra, >> John >>> Sent: Friday, July 29, 2005 7:20 AM >>> To: emc-p...@ieee.org >>> Subject: Request for info on CE Mark penalties >>> >>> >>> >>> Hello everyone, >>> >>> >>> Does anyone have any good articles or website examples of the >> penalties for >>> non- conformance for the CE Mark. I especially need examples for EMC >>> violations to use to stress the seriousness and impact to business >> for >>> some non regulatory people here who need some convincing. >>> >>> >>> Thanks in advance for your help >>> >>> >>> >>> >>> >>> John Tyra >>> Manager Product Safety >>> >>> >>> Bose Corporation >>> The Mountain, MS-450 >>> Framingham, MA 01701-9168 >>> >>> >>> Phone: 508-766-1502 >>> Fax: 508-766-1145 >>> >>> >>> ---------------------------------------------------------------- This >>> message is from the IEEE Product Safety Engineering Society emc-pstc >>> discussion list. Website: http://www.ieee-pses.org/ >>> >>> >>> To post a message to the list, send your e-mail to emc-p...@ieee.org >>> >>> >>> Instructions: >> http://listserv.ieee.org/listserv/request/user-guide.html >>> >>> >>> List rules: http://www.ieee-pses.org/listrules.html >>> >>> >>> For help, send mail to the list administrators: >>> >>> >>> Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org >>> >>> >>> 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://www.ieeecommunities.org/emc-pstc >>> >>> >>> ---------------------------------------------------------------- This >>> message is from the IEEE Product Safety Engineering Society emc-pstc >>> discussion list. Website: http://www.ieee-pses.org/ >>> >>> >>> To post a message to the list, send your e-mail to emc-p...@ieee.org >>> >>> >>> Instructions: >> http://listserv.ieee.org/listserv/request/user-guide.html >>> >>> >>> List rules: http://www.ieee-pses.org/listrules.html >>> >>> >>> For help, send mail to the list administrators: >>> >>> >>> Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org >>> >>> >>> 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://www.ieeecommunities.org/emc-pstc >>> >>> ---------------------------------------------------------------- >>> This message is from the IEEE Product Safety Engineering Society >>> emc-pstc discussion list. Website: http://www.ieee-pses.org/ >>> >>> To post a message to the list, send your e-mail to emc-p...@ieee.org >>> >>> Instructions: >> http://listserv.ieee.org/listserv/request/user-guide.html >>> >>> List rules: http://www.ieee-pses.org/listrules.html >>> >>> For help, send mail to the list administrators: >>> >>> Scott Douglas emcp...@ptcnh.net >>> Mike Cantwell mcantw...@ieee.org >>> >>> 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://www.ieeecommunities.org/emc-pstc >>> >> >> ---------------------------------------------------------------- >> This message is from the IEEE Product Safety Engineering Society >> emc-pstc discussion list. Website: http://www.ieee-pses.org/ >> >> To post a message to the list, send your e-mail to emc-p...@ieee.org >> >> Instructions: > http://listserv.ieee.org/listserv/request/user-guide.html >> >> List rules: http://www.ieee-pses.org/listrules.html >> >> For help, send mail to the list administrators: >> >> Scott Douglas emcp...@ptcnh.net >> Mike Cantwell mcantw...@ieee.org >> >> 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://www.ieeecommunities.org/emc-pstc >> > > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. Website: http://www.ieee-pses.org/ > > To post a message to the list, send your e-mail to emc-p...@ieee.org > > Instructions: http://listserv.ieee.org/listserv/request/user-guide.html > > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > > Scott Douglas emcp...@ptcnh.net > Mike Cantwell mcantw...@ieee.org > > 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://www.ieeecommunities.org/emc-pstc > This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to emc-p...@ieee.org Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas emcp...@ptcnh.net Mike Cantwell mcantw...@ieee.org 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://www.ieeecommunities.org/emc-pstc
