The BS 3900-F2-1973 standard specifies the test method for the Humidity (cyclic condensation) tolerance performance of Coating film durability tests. This method evaluates the humidity resistance and durability of films by simulating the cyclic condensation environment under high Humidity conditions. The standard describes in detail the test device, specimen preparation, test conditions and evaluation of results, and is suitable for Coating development, quality control and application performance verification. This test provides a scientific basis for evaluating the long-term Stability and protective performance of films in humid environments. It is widely used in construction, industry and Miscellaneous areas that require coating protection to ensure the Reliability and service life of Coatings.