Ferromagnetic sheets thickness measurement - uses excitation magnet and determines saturation flux for sheet

摘要

The magnet magnetises the metal sheet up to saturation, and the saturation flux is used as the measure for the sheet thickness. In order to correct the error introduced, in spite of saturation, by variations of the air-gap between the excitation magnet and the metal sheet, the air-gap is measured. The result of measurement of the air gap is displayed and/or supposed on the thickness measurement result to achieve the desired correction for the influence of the air gap.