Just as for EMC , if product failure of aging devices was a real problem, we all would have heard lots about it by now and legislation would have followed. It must be rare, and EMC or product safety might be an issue on some products with poor quality control. It just doesn't 'appear on the radar screen' as it were. However, I have seen circuit boards in some televisions which have discolouration in some areas, indicating to me that they likely never met their temperature limits, or that design changes were made after approvals which caused significant overheating of the FR4 in normal use. _____________________________________________________________________________________
Ralph McDiarmid | Schneider Electric | Renewable Energies Business | CANADA | Compliance Engineer From: Mark Schmidt <[email protected]> To: [email protected] List-Post: [email protected] List-Post: [email protected] List-Post: [email protected] Date: 06/15/2010 12:15 PM Subject: Re: [PSES] EMC Performance Changing With Age Of Product ________________________________ Just throwing this out there - how about Safety and EOL (End of Life). Let’s see quarterly inspection. Recertification (CB SCHEME) certs every three years, possible re-evaluation even though nothing has changed. More money spent. What’s the difference between this and EMC? Maybe I am missing something. In many cases the potential for EMC profile changes are greater due to the newer technologies and obsolescence of digital components. Yet no need to control EMC performance with the exception of the good honest integrity of most Regulatory Compliance (EMC) personnel/departments. Why is it different for Safety? Safety people have just as much integrity? Thoughts? Regards, Mark From: [email protected] [mailto:[email protected] <mailto:[email protected]> ] On Behalf Of [email protected] Sent: Tuesday, June 15, 2010 1:08 PM To: [email protected] Subject: Re: [PSES] EMC Performance Changing With Age Of Product Even if it were found necessary to control EMC performance of a product over its functional lifetime, I don't see how that could be done in practice. If it were common place that older electronic products became a RF nuisance, surely they would be evidence by an abundance of complaints to the authorities. Electrolytic capacitors and solder or mechanical connections do fail over time, but I suggest when they do the device likely also fails to function and is taken out of service. The apparent lack of legal control of EMC of products over their service life may simply indicate that none is warranted. _____________________________________________________________________________________ Ralph McDiarmid | Schneider Electric | Renewable Energies Business | CANADA | Compliance Engineer From: John Woodgate <[email protected]> To: [email protected] List-Post: [email protected] List-Post: [email protected] List-Post: [email protected] Date: 06/15/2010 03:44 AM Subject: Re: [PSES] EMC Performance Changing With Age Of Product ________________________________ In message <[email protected]>, dated Tue, 15 Jun 2010, "Pawson, James" <[email protected]> writes: >EMC performance of a product is likely to vary with age as the physical >characteristics change e.g. caps dry out, metal junctions oxidise, etc. > >Obviously the product is designed with the intention of consistent >compliance over the life of the product, but are there any requirements >or guidance relating to preventing or controlling this change in EMC >performance over time? Americas or Europe? I don't want to comment on the Americas position. For Europe, there seems to be an on-going problem that no-one wants to resolve, at least in some countries. For example, in UK, the Wireless Telegraphy Acts (WTA) used to apply legal controls to sources of interference, regardless of the age of the product or anything else. When the (second) EMC Directive was introduced, applying to products in general, not a specific range, those parts of the WTA seem to have been repealed. However, the EMC Directive applies requirements to *manufacturers (and/or their agents)* only. It isn't helpful to ask whether the Directive applies to newly-sold products or throughout their life. The requirements for manufacturers can only possibly apply *while the product is under the manufacturer's control*. It is reasonable to hold that the manufacturer must not neglect the reliability of any parts that affect EMC, but it is not possible to ensure that a given part will not fail very early in life. It is also not possible for the manufacturer to control what a user might do to or with the product (e.g. just connect a signal generator to an antenna and modulate it with audio). So effectively there appears to be no legal control in UK of the EMC performance of products during their life, and the same applies to any other EU state that changed its legislation in the way the UK did. If anyone believes differently, please respond (politely). -- 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. 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To post a message to the list, send your e-mail to <[email protected] <mailto:[email protected]> > All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc <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/ <http://www.ieee-pses.org/> Instructions: http://listserv.ieee.org/request/user-guide.html <http://listserv.ieee.org/request/user-guide.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: Scott Douglas <[email protected] <mailto:[email protected]> > Mike Cantwell <[email protected] <mailto:[email protected]> > For policy questions, send mail to: Jim Bacher <[email protected] <mailto:[email protected]> > David Heald <[email protected] <mailto:[email protected]> > ________________________________________________________________________ This email has been scanned for SPAM content and Viruses by the MessageLabs Email Security System. ________________________________________________________________________ - 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] <mailto:[email protected]> > All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc <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/ <http://www.ieee-pses.org/> Instructions: http://listserv.ieee.org/request/user-guide.html <http://listserv.ieee.org/request/user-guide.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: Scott Douglas <[email protected] <mailto:[email protected]> > Mike Cantwell <[email protected] <mailto:[email protected]> > For policy questions, send mail to: Jim Bacher <[email protected] <mailto:[email protected]> > David Heald <[email protected] <mailto:[email protected]> >
