Measuring Magnetic Permeability of Monolithic Annular Measures in Alternating Magnetic Fields

Abstract

A method is described for measuring the relative magnetic permeability of monolithic electrically conductive annular samples in an alternating magnetic field with a frequency of 50 Hz to 5 MHz, using toroid coils wound round the samples. The reasons are indicated for the significant influence that the electrical conductivity of the samples has on the results of measurements. The proposed procedure makes use of a correction coefficient, which depends on the specific electrical conductivity of the sample and is determined from a two-dimensional calibration table obtained by finite element modeling of this measurement problem, with allowance for the deviation of the geometrical dimensions of the measured sample from the dimensions of the sample in the finite element model.