On predicting the effectiveness of magnetic shields at low frequencies

An exact analysis of the static magnetic field penetration through a planar foil of magnetic material is presented. A formulation for the magnetic field penetration through a sheet of ferromagnetic material from a current-carrying wire oriented parallel to the sheet is developed. Questions of nonlinear characteristics and saturation are addressed. Results are provided for a few commercially available materials. A shield design procedure is also suggested.<<ETX>>