Magnetic measuring method of coating thickness

Coating thickness can be measured only on the assumption of the free surface of coating. For that reason it is possible to use only the indirect measuring methods. Such method is also the magnetic attraction principle of measuring the coating thickness. In the research are presented the theoretical basis of magnetic attraction principle, analysed the input quantities in model function and their contributions to the uncertainty of coating thickness measurement. On the basis of research are given the recommendations to use the magnetic attraction principle for coating thickness measurements. There are also presented the results of calibration of specific type of coating thickness gauges and given the recommendations for calibration this type of gauges.