At 12:51 PM 10/29/2013, Louis Hone wrote:
>It's been a while since I've baked tapes in the oven. I'm about to embark
>on a project that involves baking half a dozen Ampex 456 quarter inch tape
>on 10.5 inch reels. We have a new kitchen oven that has a dehydrate setting
>(130 degrees F) so it seems perfect for the job. However, I notice that my
>Trifield Meter indicates that the magnetic field is way over 100
>milliGauss. My old oven in which I baked many tapes, probably had the same
>reading but I never measured it. I'm not too thrilled subjecting a master
>tape to such a strong field. Has anyone else ever measured the magnetic
>field of their kitchen or tape baking oven/dehydrator ?

100 milliGauss is unlikely to damage a tape.  The earth's magnetic field is 
(in round numbers) 500 milliGauss, and it doesn't damage tapes.  It's a 
static field, so it doesn't show up on your meter, but a static field is 
equally capable of damaging a tape.  If 500 milliGauss could damage a 
recording, tape recording would not have been very useful.

-- John Chester