Coating application can be verified by both total coating weight and coating thickness.
Coating weight is determined on a test panel or part with a known surface area is first weighed as-is. After soaking in the prescribed environment for a defined period of time, the sample is weighed again and coating weight loss is calculated per area. Acid solution and temperature are selected based on the coating material.
Coating thickness may be determined by cross section and microscopic analysis. Sample preparation creates a perpendicular cross section which is then mounted and polished per ASTM E3.
Cross sectional analysis is highly effective in confirming coating thickness requirements in critical areas.