... method, can detect the thickness of non-conductive coating (such as:rubber, paint, plastic, anodic oxide film,etc) on non- ... steel, etc.) and the thickness of non-conductive coating (such as:rubber, paint, plastic, anodic oxide film,etc) on non-magnetic ... iron and other magnetic metal matrix,such as paint,a variety of anti-corrosion coating powders, plastic, rubber, synthetic materials, phosphide ...