This standard provides standard test methods for determining the water vapor transmittance of transport containers, including constant and cyclic test atmospheres. The tests cover two methods: Method A for recloadable containers and Method B for containers not designed for reclosure. These test methods are used to evaluate the performance of container materials and constructions, compare the protective capabilities of different containers, ensure adequate protection of specific products, and maintain quality control. Testing can be performed after Encasement or after Miscellaneous performance testing, such as rollers, vibrations, drops, etc. The standard conforms to the principles of international standardization and is applicable to ensure moisture resistance performance of transport containers.