The method, apparatus and the use of the device for non-destructive quantitative determination of layer thicknesses of a body having layers

摘要

A method for schichtdickenbestimmung.an a built up of at least two layers of the test specimens (4), with an outer cover layer (1) and a in relation to the cover layer is arranged deeper in the test specimens base layer (2), wherein the cover layer and the base layer of different magnetic properties and composition of matter having the following steps:- Generating a magnetic alternating field in the test specimens;- Measuring the magnetic field strength at or near the surface of the test specimen;- Measurement of at least one, preferably a plurality of pairs of values of the harmonic salary of the time signal of the tangential magnetic field strength in a function of the magnetic field strength;- Measurement of at least one, preferably a plurality of pairs of values of the via mounting permeability as a function of the magnetic field strength and- Determining the thickness of the outer layer (1) and / or of one or more other layers arranged in the test body by means of a statistical analysis method, with the measured value pairs of the harmonic salary of the time signal of the tangential magnetic field strength and then="21" By way of mounting permeability or of the pairs of values derived function of characteristic quantities as the input variables.