Ahh, the susceptibility dilemma, who is staying alert enough to notice the anomaly? At the automotive test lab, we had the tech, who also setup the recorders, video and other digital monitoring, so for the EUT engineer or whoever, could sit and review the whole long freaking test, or jump to the techs inserted flags for anomalies. Those software guys take so long to develop code, that we'd be somewhere into the next century waiting on a test setup that caught the anticipated excursions, nevermind the un-anticipated excursions from the expected norm. So the results and performance is documented as completely as we have equipment for and sent on as part of the test report.
- Bill In the event of a national emergency, click on the following links to provide directions to your duly elected mis-representative. http://www.usa.gov/Contact/Elected.shtml or... https://writerep.house.gov/writerep/welcome.shtml http://www.senate.gov/general/contact_information/senators_cfm.cfm ________________________________ From: Ken Javor <ken.ja...@emccompliance.com> To: EMC-PSTC@LISTSERV.IEEE.ORG Sent: Sat, February 6, 2010 3:03:47 AM Subject: Re: Agency Probes Gas Pedals' Link to EMI But that's like saying, yes it is possible that it will rain in Death Valley, when inquiring if damage to a domicile might have been caused by a hurricane. The real question, given present automotive EMI standards, is "What is the probability that a real world threat exceeded the stress levels imposed during radiated susceptibility qualification (which runs 100 V/m or higher to my knowledge)?" A related question is, how well was the radiated/conducted susceptibility test pass/fail criteria monitoring system designed? A well-designed test would have pre-determined pass/fail limits imposed and any excursion outside these boundaries would be automatically detected (no human in the detection loop) and flagged. NOT saying this was the case here - no idea about that - just using this issue as an example of the fact that every EMI standard of which I am aware leaves completely uncontrolled the issue of assessing susceptibility/immunity. While it is obvious that specific conditions cannot be levied in the general case, that is no excuse for not requiring automated detection/flagging so that the quality of the test is not resting on the unflagging vigilance of some poor sap with his/her eyeball glued to an oscilloscope or DMM display, eight hours a day, five days a week. Spending $300 US an hour and days on end doing a test whose ultimate validity rests on such a shaky foundation is utter folly. That said, I serve on various standard-generating committees and have never convinced one to take this on and put teeth in it. Ken Javor Phone: (256) 650-5261 > From: John Woodgate <j...@jmwa.demon.co.uk> > Date: Sat, 6 Feb 2010 07:21:42 +0000 > To: <EMC-PSTC@LISTSERV.IEEE.ORG> > Subject: Re: Agency Probes Gas Pedals' Link to EMI > > In message <DB013042D97E40228C280F9506B00198@christopher>, dated Sat, 6 > Feb 2010, Chris Wells <radioactive55...@comcast.net> writes: > >> Could EMI interfere with communications between throttle sensor to CPU >> or CPU to motor? > > By definition! It isn't EMI if it doesn't. Even when replacing 'EMI' > with 'EM disturbance', it's still true, because there is no limit to the > strength of a disturbance and nothing using electrical conduction has > infinite immunity. > -- > OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk > John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK > I should be disillusioned, but it's not worth the effort. > > - > ---------------------------------------------------------------- > 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.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 <emcp...@socal.rr.com> > Mike Cantwell <mcantw...@ieee.org> > > For policy questions, send mail to: > Jim Bacher: <j.bac...@ieee.org> > David Heald: <dhe...@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.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 <emcp...@socal.rr.com> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@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.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 <emcp...@socal.rr.com> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <j.bac...@ieee.org> David Heald <dhe...@gmail.com>
