GB/T 16928-1997 is a test method standard for the moisture permeability of Encasement materials. It describes the principle of moisture permeability measurement and lists the required instruments in detail, such as moisture permeable cups, drying agents, etc. The standard strictly stipulates the test process, from Sample Handling, installation to test operation under different environment conditions, there are clear step instructions. Testing according to this standard can accurately obtain the moisture permeability data of Encasement materials, which provides a key reference for Encasement design, material selection and product moisture resistance performance evaluation. It helps to extend the shelf life of products and ensure that the mass of products in storage and transportation is not affected by Humidity.