Importance of Coating Weight and Thickness Testing
ATS performs coating weight and thickness testing to determine the mass of anodized aluminum, phosphated, chromated, painted, and aluminized or galvanized steel for comparison with specification requirements.
In addition to the natural barrier protection of the coating, zinc on iron or steel also provides sacrificial protection against corrosion, the degree of protection being proportional to the thickness or the weight of the coating. A variety of specifications provide different classes of coating so our customers should select the coating weight that is most suitable for the environment (industrial, marine, rural, tropical, etc.) and their product’s application.
One of the most common zinc coatings is Class G90, which has 0.9 oz/sq. ft. (total both sides of the sheet) or about 0.80 mils per side. The typical applications of galvanized sheet steel are in car bodies, appliances, corrugated roofing, garage doors and duct work.
Some of the regularly used test methods that ATS carries ISO 17025 accreditation by A2LA are; ASTM D7091 (Nondestructive Measurement of Dry Film Thickness of Coatings Applied to Ferrous and Nonferrous Metals), ASTM A90 (Measurement of Coating Weight on Galvanized Articles), and ASTM B137 (Measurement of Coating Mass on Anodized Aluminum).