In message <4c5e6457cd7911469a07260381288c282157e...@orsmsx502.amr.corp.intel.com>, dated Wed, 11 Feb 2009, "Pettit, Ghery" <[email protected]> writes:
>QP detector time constant is called out in CISPR 16-x-y, not in CISPR >22 (or CISPR 32). Remember, the weighting function in the QP detector >originally simulated the response of a physical meter with mass that >limited its response to short duration signals. These short duration >random noise events might not have even registered on such antiques. Well, not really a low-performance 'antique' meter. To meet the 1 ms requirement in CISPR 16-1-1, a very special meter was needed, with a very strong magnet and a very light coil. > >The text proposed in CISPR 32 (latest draft) is a clarification of text >that has been in CISPR 22 for over 15 years (and possibly 24 years). I >guess I'm not sure just what problem has cropped up in the field that >this hasn't adequately addressed. The more people that read standards and the more standards they read, the more queries arise about undefined requirements and loose terminology. The position is not being improved by the very strong time-pressure being applied by standards body administrations and the lack of people to do proper editing. It's a skill that not everyone possesses. > >This is not a change to a measurement method, it is a clarification of >a long standing bit of guidance on interpreting results of a test. It's a clarification, yes, but the 'guidance' is clearly so vague that it is not real guidance at all. This sort of thing didn't matter too much when the only enforcement of compliance was contractual, because the parties could agree to interpret, or even disregard, doubtful wording. But now compliance is effectively a de facto legal requirement (even if not de jure), these poor texts create doubt and despondency. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Things can always get better. But that's not the only option. 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.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]>
