... zinc, aluminum, chromium, copper, rubber, paint etc.) on magnetic metal matrix iron (such as: iron, steel, alloys and hard-magnetic steel ... zinc, aluminum, chromium, copper, rubber, paint etc.) on magnetic metal matrix iron (such as: iron, steel, alloys and hard-magnetic ... phosphide layer, chromium, zinc, lead, tin, cadmium and so on.Measuring all non-conductive layer thickness of copper ,aluminum, ...