... (such as iron, nickel) non-magnetic coverage layer (such as: paint, plastic, enamel, copper, aluminum, zinc, chromium, etc.). It not only ... can be applied to measure the thickness of plating layer, paint layer, porcelain enamel layer, aluminum tile, copper tile, Babbitt ... can be used to measure the thickness of ship body paint and of the attachment of underwater hull structural parts.With spring ...