Patent ID: 8148976

Claim:
A method for the contactless determination of properties influencing the conductance of an electrically conductive substance moving in a primary magnetic field (B), comprising the following steps: coupling a primary magnetic field (B) into a substance being inspected using a magnetic system with at least two poles, wherein lines of force of the primary field (B) running in an air gap between the at least two poles penetrate the substance and run substantially transverse to a direction of movement of the substance; measuring at least one mechanical state parameter of the magnetic system, the at least one mechanical state parameter changing due to an action of a secondary field on the magnetic system, the secondary field being formed by eddy currents induced in the substance by the primary field (B); calculating at least one property influencing a conductance of the substance method of least error squares, wherein a function being minimized is a mean square deviation of the at least one state parameter as calculated by an assumed spatial distribution of the at least one property of the substance being inspected from the respective measured state parameters.