Measuring coercive field strengths on extensive surfaces - by quasi-stationary and dynamic cycling through hysteresis curve

A method of determining the coercive field strength on extensive surfaces with mangetoinductive and magnetoelastic measurement parameters involves quasi-stationary and dynamic cycling through the hysteresis curve. It enables the hitherto necessary special calibration procedures and strong geometric dependency to be eliminated. The method involves use of the fact that the maxima of the reversible permeability over the tangential field strengths coincide with the coercive field strengths. The maxima of the superposition permeability over tangential field strength coincide with the actual coercive field strength values up to a deviation of half the peak-to-peak residual alternating field amplitude. Because the reversible permeability can by definition only be measured in the limiting case where the residual field magnitude tends to zero, the superposition permeability is measured in practice.