Equipment for the magnetization characteristic evaluation of a ferromagnetic body

In order to perform the magnetic field computation it is essential to know the B-H characteristic. This paper presents a new equipment to be used to determine the first magnetization characteristic of a ferromagnetic body. This equipment consists of an 8-shape magnetic circuit, having as unknown the B-H magnetic characteristic in the base horizontal yoke. The other branches have a known B-H characteristic, and on the median yoke there is an air gap where the magnetic flux can be measured. The magnetic circuit windows contain two coils circulated by two different direct currents, with their values adjusted in such a way that the magnetic flux from the air gap to be zero. The B-H characteristic evaluation consists in the computation of a magnetic field inverse problem, for which one determines small linear portions of this characteristic. The search of those linear portions takes place in a successive manner, the slopes corresponding to these characteristics being established such that the flux in the air gap to be zero. To test the procedure, one chooses a sample having a known B-H characteristic and, from the computation, the pairs of currents (i₁, i₂) for which the magnetic flux from the air gap is zero are determined. These pairs of currents play the role of the currents measured by the real equipment. Then, starting from these pairs one determines the B-H characteristic.