Magnetic Shielding Effectiveness and Application of 0.003% Carbon Steel Foil

Magnetic shielding characteristics using magnetic sheets are described for high fields of about 1000 Oe and an application to the magnetic card shielding is shown. The magnetic shielding effectiveness at high fields depends on the saturation flux density of soft magnetic materials. 0.003% carbon steel foil has a good magnetic shielding effectiveness compared with mumetal or an amorphous alloy because of its high saturation flux density. It is necessary to use the 0.35 mm thick 0.003% carbon steel foil to shield the magnetic card media from the high external magnetic field.