At one point, I was an EMC Design Engineer working for an EMC Test Lab. We provided both services to the customer. But also provided a certain divide within our Test Lab in that we had to provide for a certain degree of separation between my design suggestions and the test results. Personally I have no problem with recommending a design and consequently failing or passing it, just as the data says. But for Corp purposes, if I had suggestions that the customer implemented, the other engineers ran the tests, and the techs that did the actual testing reported to another managment chain. So we had a three way separation of design and test. And if the customer called in an independent consultant, I could only exchange pleasantries with him. To protect the Labs reputation, all this was closely and visible monitored, thus the 3 way. Otherwise, the mitigation efforts are ferrites on cables and copper tape on seams. No conflict in that, we keep a big supply of those things... and they don't have much effect either. And damned if that wasn't exactly what the independent consultant recommended each time.
>________________________________ > From: "Kunde, Brian" <[email protected]> >To: "[email protected]" <[email protected]> >Sent: Thursday, March 14, 2013 11:16 AM >Subject: RE: [PSES] Critical component in EMC report > >John gives good advice. Send a couple of your EEs to a seminar or two. You >really cannot afford not to. > >As far as 3rd party EMC test labs, some of the larger labs do provide >engineering services, but there is a thin line of ethics they must be careful >not to cross. If you don't have or cannot have expertise in-house your best >bet is to hire an independent contractor who can help you design and produce a >compliant product. It is best if your 3rd party test lab's only responsibility >is to test and provide results. They cannot be responsible for the compliance >of your product in any way. But, they should be open to include any >information on their test reports that you need or want as long as they can >verify the information you give them is correct. > >The only way to know for sure your production is compliant is to test which >can be expensive. But knowledgeable in-house EMC expertise can pay for itself >very quickly if unnecessary testing can be avoided. Look at the Emissions test >standards such as CISPR 11 or 22 under the Assessment of Conformity of >Equipment section. It talks about the 80/80 rule and says something like, >"measurements shall be performed on a sample of not less than five and not >more than 12 pieces....". The EMC Directive in Europe says, "The manufacturer >must take all measures necessary to ensure that the products are manufactured >in accordance with the technical documentation referred to in point 3 and with >the provisions of this Directive that apply to them." > >I am a strong advocate of testing, testing, testing. We pretest everything we >can; power supplies, modules, pc cards, controllers, hard drives, etc.. We >test engineering prototypes, pre-production, and first production products. >And we have an annual audit program to insure our production remains >compliance. And of course we test any major change that we feel can affect >compliance; a decision that can only be made from our many years of experience >and familiarity with our products. Something you cannot get from a 3rd party >lab or consultant. > >The Other Brian > > >-----Original Message----- >From: [email protected] [mailto:[email protected]] On Behalf Of John Woodgate >Sent: Thursday, March 14, 2013 10:13 AM >To: [email protected] >Subject: Re: [PSES] Critical component in EMC report > >In message <cd67f0b2.1981a%[email protected]>, dated Thu, 14 Mar 2013, Scott >Xe <[email protected]> writes: > >>For medium and small companies, they have no test facilities and the >>engineers who may not have got the professional training in EMC >>requirements > >BAD!!!! Train them. It saves money, time and heartache. > >>rely on the 3rd party lab for spotting out the failures and the advice >>for problem fixing. Dealing with such companies would be at risk as >>the test report may not help them too much. > >Indeed: corporate confidence is bound to be damaged when no-one knows if the >latest product will pass or be an EMC or safety basket-case. >-- >OOO - Own Opinions Only. See www.jmwa.demon.co.uk SHOCK HORROR! Dinosaur-like >DNA found in chicken and turkey meals John Woodgate, J M Woodgate and >Associates, Rayleigh, Essex UK > >- >---------------------------------------------------------------- >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 > >Attachments are not permitted but the IEEE PSES Online Communities site at >http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used >formats), large files, etc. > >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]> >________________________________ > >LECO Corporation Notice: This communication may contain confidential >information intended for the named recipient(s) only. If you received this by >mistake, please destroy it and notify us of the error. Thank you. > >- >---------------------------------------------------------------- >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 > >Attachments are not permitted but the IEEE PSES Online Communities site at >http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used >formats), large files, etc. > >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.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. 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]>
