In message <[email protected]>, dated Fri, 24 Feb 2006, Robert A. Macy <[email protected]> writes
>No, from the little magnet inside the speedometer spinning around in >front of you. H'mmm: I don't understand that; the magnet isn't very strong and it's a long way from even the driver's hands. The ICNIRP Guidelines are of some significance to me at present, and I just don't see 10 A/m (12.6 microtesla) there. I'm (slowly) building an omnidirectional magnetometer for fields up to 1000 A/m, but I don't have an eddy-current speedo to test. Maybe an excuse to buy a classic car on the company account? > >You're right, I wasn't clear about the origin of the magnetic field. >Main reason I'm not allowed to write legal specifying thingies. Try a short 40-year course of writing standards. (;-) > >Regarding the earth's field, the steel tends to "short" out the earth's >field. It gets in through the windows, though. And although it varies from place to place, a value of 40 A/m is not uncommon. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk 2006 is YMMVI- Your mileage may vary immoderately. John Woodgate - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] 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] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
