Determination of magnetic field intensity on open sample

The work is focused on the refinement of the determination of the magnetic field intensity in a Charpy-shaped steel sample. When measuring on an open sample, the intensity of the magnetic field cannot be determined directly from the current by the magnetizing winding. The distribution of the magnetic field around the sample was determined by numerical simulation, the dependence of its intensity on the distance from the sample surface is fitted with sufficient accuracy by a polynomial of the 3rd degree. A system of sensors sensing the distribution of the field at selected points above the sample was designed; by extrapolation using said fitting function, the intensity of the magnetic field on the surface of the examined sample is determined.