... current principle to measure in a non-destructive way Coating Thickness Gauge I. Measuring PrincipleThe instrument adopts the magnetic and eddy ... base (e.g. zinc, aluminum, Cr. Copper, rubber, paint, coating on the base of steel, iron, alloy and hard ... all electrically insulating coating layers, such as lacquer, Varnish, paint, anodizing coating on nonferrous metals, also on austenitic VA steel ...