On Aug 1, 2:24 pm, Nick Mueller wrote:
Nick Mueller wrote:
It is. A bit. The right word to look for in wiki is susceptibility.

Just came to my mind:
Brass is halfway good for shielding magnetic fields, copper is better. But
you have to make a closed case. Not applicable in your case.
Materials out of my head, I might be wrong. Once made a shielding case for
measuring cellulars and researched a bit into that. In the case of radio
waves, things are a bit more complicated, because there are magnetic and
electric fields.

The magnetic field that represents a radio wave generates a
current in the shielding material, whether it's aluminum or copper or
whatever, and this current is grounded, effectively killing the
field's effect on whatever the shield is protecting. A common example
is shielded ignition wires used in aircraft to stop radio noise.
I would expect that a magnetic field passed through an aluminum
plate would have no loss of strength UNLESS the plate or magnet was
rotating, whereupon an eddy current would be generated that would
likely heat the aluminum somewhat. That heating would represent some
loss of field strength through the aluminum. The current generated in
a wire's shielding is created as a result of the AC nature of the
field, which has the same effect as relative movement between the
field and shielding.

Dan