... (e.g. paint,plastic, porcelain enamel, copper, zinc,aluminum , chrome etc.) on magnetic materials (e.g. iron, ... layer,porcelain enamel layer, phosphide layer, copper tile, aluminum tile, some alloy tile, paper etc. The N probes measure the thickness ... varnish, paint, enamel,plastic coatings, powder, etc. applied to aluminum, brass, non-magnetic stainless steel, etc. Automatic substrate recognition ...