Original poster: "Bob (R.A.) Jones" <a1accounting@xxxxxxxxxxxxx>
Hi,
The shielding effectiveness of a infinite metal sheet to a magnetic field is
a function of the skin depth in the metal at the frequency of the magnetic
field. If the thickness of the sheet relative to skin depth is small the
shielding will not be effective. (say 10% reduction) If the thickness of the
metal sheet is large relative to the skin depth the shielding will be very
effective (say 90% reduction). From memory the skin depth in aluminum at the
usually Tesla coil frequencies is less than a 1mm so 1mm of aluminum sheet
should reduce the field to say less than 10%. Other factors such as joints
and size of the shield will have an effect as well.
Robert (R. A.) Jones
A1 Accounting, Inc., Fl
407 649 6400