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