This standard provides a basic method for testing coating water resistance in a water mist environment. By exposing coating samples to water mist and evaluating their water resistance performance, the test results can be used for research and development, quality control and specification acceptance of coatings and substrate treatments. Water mist testing equipment is similar to salt spray testing equipment, pay attention to remove salt traces. This method is suitable for evaluating water resistance of individual coatings or complete coating systems, but the test results are not a complete substitute for actual water exposure in the natural environment.