... field conditions.The F probes measure the thickness of non-magnetic materials (e.g. paint, plastic, porcelain enamel, copper, ... tile, some alloy tile, paper etc.The N probes measure the thickness of non-magnetic coatings on non-magnetic metals. It ... plastic coatings, powder, etc. applied to aluminum, brass, non-magnetic stainless steel, etc.Automatic substrate recognition.Manual or automatic shut down ...