Messverfahren und Anordnung zur Bestimmung metallischer Oberflächenschichten auf metallischen Werkstücken

摘要

The invention relates to a measuring method for determining metal surface layers (2) on metal workpieces (1). The measuring method is especially suitable for determining the thickness of chrome coatings on brass workpieces or for determining the diffusion coating thickness of nitride steels. For carrying out said method, current flows (I) are generated by passing defined heat quantities (Q) into the boundary surfaces between surface layer and workpiece and the magnetic fields (H) surrounding said current flows are read out to determine the surface layer thickness. The inventive method is characterized by passing the heat quantities either into two defined points of the surface of the surface layer or into one point of a workpiece edge. When heat is passed into the surface layer in two points, two heat quantities with different preceding sign are used. The system comprises at least two elements (3, 4) for passing defined heat quantities into the surface of workpieces and a device (5) for detecting magnetic fields. The elements are placed on the surface of the workpiece at a distance to each other.