Non-destructive thickness measurement of non-magnetic coatings, e.g.: zinc, copper, chrome, cadmium, etc. Also paint enamel, plastic, etc. on iron and steel. The measurement of film thickness depends on the degree of magnetic attraction to a surface. The attraction depends on the distance of a permanent magnet from a steel surface. This distance represents the thickness of a non-magnetic coating. No power supply or calibration necessary. Operating temperature –20oC to 100oC.