I don't know what the commercial standards require, but for instance MIL-STD-461 has the field intensity (Tesla) limit augmented by a precise description of the coil diameter to be used when generating the field. This completes the requirement and makes it repeatable across test facilities.
> From: John Woodgate <[email protected]> > Date: Wed, 4 Jul 2007 17:44:42 +0100 > To: [email protected] > Subject: Re: Please reply to me (Magnetic Field testing ) > > In message <c2b13257.58e9f%[email protected]>, dated Wed, 4 > Jul 2007, Ken Javor <[email protected]> writes: > >> I have no idea what is being requested here, but from a technical >> standpoint it is insufficient to specify a magnetic field alone; > > But this is exactly what EMC immunity standards specify (either H in A/m > or B in tesla). Since dB/dt is strictly proportional to d(phi)/dt in > space or air, there doesn't seem to be any need to appeal to phi > directly > >> it is important to specify over what area (magnetic flux) the magnetic >> field intensity must be induced, since coupling from magnetic fields is >> proportional to the time rate of change of magnetic flux (Faraday) not >> the field intensity alone. > > The implication, surely, is that the product is subjected to a > homogenous field of an area at least as large as the plane projection of > the product in the direction of the field. > -- > OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk > There are benefits from being irrational - just ask the square root of 2. > John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK > > - > ---------------------------------------------------------------- > 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 - 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 ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________
