Which instrument is used to verify the film thickness during the painting process?

• A. Wet Film Thickness Gauge
• B. Thermometer
• C. Caliper
• D. Hygrometer

Answer: (A)

Measuring how thick the paint is while it’s still wet is essential to ensure the final coating dries to the required thickness. A wet film thickness gauge is built for this purpose and gives a direct reading of the paint layer’s thickness on the surface. By comparing that reading to the target wet film thickness, you can control application speed, amount of paint applied, and pass/fail criteria in real time, helping to achieve a consistent, compliant coating.

The thermometer measures temperature, which influences viscosity and cure rates but not the film’s thickness. The caliper checks dimensions of solid parts, not a thin liquid film. The hygrometer gauges environmental humidity, which affects drying behavior but not how thick the film is.