Ken, I don't think anyone is admitting hazard from a dc mag. Field, only regulatory impact.
Scott, We have been challenged on this count because some large steel machine frames we wanted to ship had a very small residual mag field, either native in the steel stock or induced by welding. It was a surprise, to say the least. Measure your items as they are going to be shipped. That is, packed in their packing crate. You may be able to use magnetic shunts, or the physical arrangement of the magnets to lessen the extent of the field outside the shipping crate. It think self-measurement is okay - you will be accountable for your shipments, no matter who measures. The acceptability thresholds are so low, you should measure with a stationary meter that has been zero'ed out to local fields. Then introduce your crate into range at proper distance, setting it on something that can turn. Turn the crate for your 360, don't move the meter. Cheers, -- Lauren Crane (mr.) Product Regulatory Analyst | Corporate Product EHS | Applied Materials Office 512.272.6540 | Mobile 512.736.7201 | America - Europe - Asia -external use- ** Save paper and trees! Please consider the environment before printing this e-mail. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Ken Javor Sent: Monday, July 25, 2011 10:32 AM To: [email protected] Subject: Re: Loudspeaker Certification as Dangerous goods Everyone seems to acknowledge some hazard from a dc magnetic field. For my own edification, other than compass-safe distance, what is the hazard of a dc magnetic field to an aircraft? Ken Javor Phone: (256) 650-5261 > From: Doug Kramer <[email protected]> > Date: Mon, 25 Jul 2011 08:55:59 -0500 > To: "[email protected]" <[email protected]> > Conversation: Loudspeaker Certification as Dangerous goods > Subject: RE: Loudspeaker Certification as Dangerous goods > > Also, keep in mind if you ship multiple speakers in a box, how they > are positioned in the box relative to each other has a huge effect on the fields. > -Doug Kramer > > -----Original Message----- > From: [email protected] [mailto:[email protected]] On Behalf Of John > Woodgate > Sent: Sunday, July 24, 2011 11:07 AM > To: [email protected] > Subject: Re: Loudspeaker Certification as Dangerous goods > > In message <[email protected]>, dated Sun, 24 Jul 2011, > Scott Douglas <[email protected]> writes: > >> Would it be necessary to measure every speaker, one of a series, or >> the biggest one we make and use that to cover all? > > The strength of the external field depends on constructional details, > not size. If you need to do tests, you need to test one of every > product (barring variants with different impedances), at least. > -- > 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 When I > point to a star, please look at the star, not my finger. The star will > be more interesting. > > - > ---------------------------------------------------------------- > 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://product-compliance.oc.ieee.org/ > 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]> > > - > ---------------------------------------------------------------- > 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://product-compliance.oc.ieee.org/ > 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]> - ---------------------------------------------------------------- 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://product-compliance.oc.ieee.org/ 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]> ________________________________ - ---------------------------------------------------------------- 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://product-compliance.oc.ieee.org/ 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]>
