What does a conductivity test assess on a cleaned bare metal surface?

A conductivity test measures the level of contamination on a cleaned bare metal surface. This is because various contaminants, such as salts and other ionic residues, can affect a metal's electrical conductivity. If these contaminants are present on the surface, they will alter the conductivity reading. A lower conductivity typically indicates a cleaner surface, whereas higher conductivity suggests retained contaminants, which may compromise the performance of subsequent coatings or treatments.

The focus of this test is on evaluating the cleanliness of the surface, since the effectiveness of paint adhesion and corrosion resistance can be severely impacted by residual contaminants. Understanding the cleanliness level of a surface is crucial in the coatings industry, as it ensures that the appropriate measures are taken before applying protective coatings. Thus, identifying contamination levels is essential for ensuring the longevity and durability of the coatings applied to the metal surface.