Test coating weight of galvalume steel sheet by Microscopy.
Microscopy is also called cross-section metallography. A inspector prepares the test sample of galvalume steel sheet or galvanized steel sheet into a cross-section sample, uses appropriate techniques to grind, polish, and etch the cross-section. The image is magnified under a microscope. The inspector use a micrometer or a high-precision ruler (such as a vernier caliper, etc.) measures the width of the cross section of the coating, which is the thickness of the coating of galvalume steel sheet or galvanized steel sheet.
Then based on the area and the density of the coating, the coating weight per unit area can be calculated.
