How To Block Or Magnetic Field?

Ferromagnetic materials can be used to shield the magnetic field, generally with an ordinary iron. But be aware of is the thickness of the plate, thickness up to, iron is magnetic saturation, only a partial shield magnetic field, part of the magnetic lines of force still emanates. Magnetic field form a magnetic circuit is the key to choose a high permeability materials and the right size and shape, magnetic flux leakage reduction, namely in the magnetic circuit of magnetic yoke and pole configured properly.