Magnet analysis with a Helmholz coil set

The magnetisation of a magnetic material can be measured using a low-cost Helmholz coil set. The resulting output, the magnetic dipole moment, is also dependent, however, on the known magnet volume, shape and its relative permeability. It is demonstrated that making two measurements with different magnet shapes and using the shape dependent demagnetisation factor suffices to get the relative permeability and remanent induction. Furthermore, it is possible to reconstruct a significant part of the B-H loop if the magnet shape allows the stacking of magnets on top of one another.