GB/T 1038.2-2022, as a specialized standard for testing the gas permeability of plastic film and sheeting, specifies two test methods: the coulometric sensor method and the gas chromatography method under isostatic conditions. It is applicable to plastic films, sheets, co-extruded materials, plastic-coated materials, laminates, etc., and can evaluate the gas permeability of materials to oxygen, nitrogen, and other gases, providing a basis for material selection in fields such as food and pharmaceutical packaging. The test requires the use of a gas permeability tester equipped with a permeation cell, a gas supply system, and a detection system. The permeating gas is carried by a carrier gas to the sensor for detection, enabling the precise acquisition of gas permeability data and providing unified technical support for quality control and performance evaluation of related products.