Analytical and FEM modelling of an electromagnetic sensor with an H-shaped ferrite core used for monitoring the hot transformation steel

This paper presents the modelling of an H - shaped ferrite core electromagnetic sensor for phase transformation detection in steel rolling application. It has been found that the response of the H - shaped sensor after normalisation can be described by a simple analytical model. Further, it has been found that the zero-crossing frequency for the real part of the inductance spectra and the peak frequency of the imaginary part of the inductance spectra for both air-cored and ferrite-cored sensors are linearly proportional to the magnetic permeability of the steel strip under test. These findings are helpful in understanding the response of the EM sensor and possibly lead to more accurate determination of steel magnetic property in an industrial setup and a convenient method for calibrating the device.