| 摘要 |
A process to distinguish plumbing parts, either individually or as combined into a plumbing product, in which one of two types of coatings have been applied to the parts, with the parts being visually indistinguishable by the type of coating. The parts are illuminated with a non-visible light operating at a frequency which will be absorbed by only one type of coating. The parts may be coated with an essentially organic coating or an essentially inorganic coating. Only one of these coatings will absorb the non-visible light and such absorption will be displayed so as to distinguish between parts having the different types of coatings. <IMAGE> |
