The ASTM D 2247-15 (2020) standard implementing procedure specifies a test method for testing water resistance of coatings at 100% relative humidity. This procedure evaluates the water resistance of coatings under wet conditions by exposing coatings to an environment of 100% relative humidity. The standard describes the test equipment, sample preparation, exposure time, and observation requirements to help determine the Stability and water resistance of coatings in long-term humid environments. This test method is widely used in the quality control of Coatings, especially in high-humidity environments, to ensure their durability and water resistance.