How do you shield magnetic fields? Anything akin to a Faraday case?

Answer 1

You use magnetic materials to make a sealed enclosure - mu metal is a common material - or you apply a magnetic field equal and opposite to the field you're trying to shield so that the net field in some volume is zero.

Answer 2

I have seen the type of magnetic 'shielding' used for the magnetic anomaly detector element from a Maritime patrol plane. It consisted of 5 concentric layers of mu metal seperated by some sort of foam spacer. The tech told my class that this is not a shield but it does reduce the influence of external fields by a major amount.

Answer 3

The only way to actually shield magnetic fields is to use superconductor material, and even then, technically this is not a shield, it's just that flux won't penetrate a superconductor.

But the practical way is to use a ferromagnetic material, such as steel or even better, mu metal. It doesn't actually shield, but what it does do is provide a very low reluctance path for flux, keeping it away from the shielded object.

Mu metal is used to shield CRTs, for example.

Answer 4

If a ring made of ferromagnetic substance is kept in the magnetic field, the lines of force will rush through the magnetic material leaving the central gap free from lines of force. The thing kept in the central space will not be affected by the lines of force.

Answer 5

I would think that you would shield a magnetic field the same way you would shield a sensitive sensor from that same kind of field, encase it with a fine metallic mesh covering and ground the covering.