Heck! We're no longer ladies, but we still get denounced! However, it is better than "burn, baby burn!" (I just wish that Bellcore would get a clue!)
Tania Grant taniagr...@msn.com ----- Original Message ----- From: John Woodgate Sent: Thursday, June 21, 2001 6:13 AM To: emc-p...@majordomo.ieee.org Subject: Re: You won't believe this ... Well, maybe you will. <oe6ymq1we9ql2rkes8y0002c...@hotmail.com>, Tania Grant <taniagr...@msn.com> inimitably wrote: > However, I believe that standards should use all three precepts as > necessary rather than an ascension order as you state. You have introduced a higher level of insight. What is *specified* is not necessarily *what is evaluated*. For example, it is required that printed circuit board material is fire-resistant according to a defined test. But it is NOT necessary to actually test it, if it is clearly made of a material known to be satisfactory. On the other hand, it is wrong to specify that it must be of grade XYZ, without the option of testing the performance of, for example, a special SHF board material that is not within the 'grade XYZ' specification because it's basically PTFE, not glass-epoxy. > > For example, for fire mitigation, UL uses all three approaches: > performance (subjects plastics to fire tests), construction (types > of enclosure, hole openings), and design (parts in low current & > power limited circuits have different requirements). > I think UL has some way to go, though, in choosing performance specifications *for preference* over construction or design. > In contrast, Bellcore GR-63-CORE torches the complete system to > prove fire safety and subjects printed circuits to airborne > contaminants (thereby absolutely destroying them) to prove pass or > fail parameters by performance. I think that it is wrong > and unreasonable to destroy equipment that costs hundreds of > thousands of dollars to prove a pass or fail condition. And > unnecessary when judicious design and construction requirements > could achieve similar results. I quite agree: such an approach does not take into account the data obtained by previous testing and certification. Specifications of construction or design in fact depend on past testing to determine 'what we know works'. > I think that all three are > necessary in proper combination. UL is not a saint, but I believe > that they have a more rational approach than burning equipment,-- > like witches were burned in the Dark Ages to prove their fair or > foul status. Agreed, especially as ladies who second-guessed men were very liable to be denounced in the bad old days. (;-) -- Regards, John Woodgate, OOO - Own Opinions Only. Phone +44 (0)1268 747839 Fax +44 (0)1268 777124. http://www.jmwa.demon.co.uk Why not call a vertically- applied manulo-pedally-operated quasi-planar chernozem-penetrating and excavating implement a SPADE? ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net 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.rcic.com/ click on "Virtual Conference Hall,"
