Determining thickness of metal oxide layer on substrate made from metal in form of nuclear fuel rod comprises using electromagnetic alternating field

摘要

Process for determining the thickness of one or more layers lying over each other on a substrate comprises producing an electromagnetic alternating field close to the outermost layer; measuring the effects of the fluidized currents produced on the alternating field; and determining the thickness of the layer(s). Measurements are carried out by adjusting the frequency of the alternating field to two different values so that the alternating field resulting from the effects of the fluidized currents is measured at theses frequency values and the thickness of the layer(s) calculated based on the data as well as the electromagnetic properties of the substrate and the layer(s). An Independent claim is also included for a device for carrying out the process. Preferred Features: Measurement of the alternating field is carried out in the frequency region of 500 kHz to 10 MHz.