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was introduced, applying to products in general, not a specific range, those parts of the WTA seem to have been repealed.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. 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.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 <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
