Search coil magnetometer

An inductive sensor connected to a conditioning electronic circuit constitutes a search coil magnetometer.

It is a vector magnetometer which can measure one or more components of the magnetic field.

A classical configuration uses three orthogonal inductive sensors.

which follows which can be expressed in a simpler way by assuming that the induced magnetic field B is homogeneous over a surface S (the magnetic flux will be expressed

) may be increased several ways: When a coil is wound around a ferromagnetic core, that increases the sensitivity of the sensor thanks to the apparent permeability of the ferromagnetic core.

The magnetic amplification, known as apparent permeability

The induced voltage will be written The demagnetizing coefficient can easily be computed in the case of simple shapes (spheres and ellipsoids).