degaussing for compass

There are direct current machines for doing magnetic
particle inspection [MagnaFlux] and these machine do have a
built in degaussing procedure with DC current.

Yes, a large coil with AC can be used to degauss by
withdrawing the coil to several feet. Putting a tool or
tube in the AC field and switching OFF will magnetize
because the induced field is cut suddenly.



"nrp" wrote in message
oups.com...
|
| opposite polarity, switch direction manually. Use less
| current (amps) with each cycle. There are machines that
do
| this automatically, but you can rig up something to do
it
| from odd bits and pieces.
| There are machines that do
| this automatically,
|
| Isn't this the 60 Hz line? Just withdrawing the coil will
fade the
| cyclic magnetic flux.
|
| BTW I had in mind a several ft diameter for the #14 wire
concept, so
| that a steel tube fuselage could be degaussed.
|

That works ... sort of. How much magnetism (if any) you get, and of which
polarity is a function of where in the waveform the coil is when you switch
the current off.

Jim



Yes, a large coil with AC can be used to degauss by
withdrawing the coil to several feet. Putting a tool or
tube in the AC field and switching OFF will magnetize
because the induced field is cut suddenly.