The NF A91-146-2006 standard deals with the inspection audit of metal cladding porosity. The standard reviews a variety of metal cladding porosity test methods, including porosity detection on various metals such as aluminum, anodic oxidation aluminum, cadmium, chromium, copper, and their alloys. These tests are designed to reveal pores and discontinuities in platings through chemical reactions to evaluate the mass of metal cladding. The standard applies to gold chromate or gold phosphoric acid salt conversion films on various base metals, as well as silver, acid, ethane nickel, and zinc alloys, among others. Impact reactions on discontinuities on substrates can be observed through these tests and evaluated in the form of reaction products.