1.1本试验方法涵盖了测定水蒸气通过柔性阻隔材料的透过率的程序。该方法适用于3 mm（0.1 in.）以下的薄板和薄膜在厚度上，由单层或多层合成或天然聚合物和箔组成，包括涂层材料。它规定了( 1. )水蒸气透过率（WVTR）( 2. )薄膜对水蒸汽的渗透性，以及( 3. )对于均质材料，水蒸气渗透系数。 笔记 1-必须小心使用水蒸气渗透性和水蒸气渗透性的值。WVTR与厚度的反比关系和WVTR与水汽分压差的直接关系可能并不总是适用。 1.2 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。 ====意义和用途====== 本试验方法的目的是获得塑料薄膜和薄板的WVTR的可靠值。 WVTR是包装材料的一个重要特性，直接关系到保质期和包装产品的稳定性。 如果买方和卖方已就取样程序、标准化程序、测试条件和验收标准达成一致，则本测试方法的数据适合作为测试的参考方法。

1.1 This test method covers a procedure for determining the rate of water vapor transmission through flexible barrier materials. The method is applicable to sheets and films up to 3 mm (0.1 in.) in thickness, consisting of single or multilayer synthetic or natural polymers and foils, including coated materials. It provides for the determination of ( 1 ) water vapor transmission rate (WVTR), ( 2 ) the permeance of the film to water vapor, and ( 3 ) for homogeneous materials, water vapor permeability coefficient. Note 1—Values for water vapor permeance and water vapor permeability must be used with caution. The inverse relationship of WVTR to thickness and the direct relationship of WVTR to the partial pressure differential of water vapor may not always apply. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. ====== Significance And Use ====== The purpose of this test method is to obtain reliable values for the WVTR of plastic film and sheeting. WVTR is an important property of packaging materials and can be directly related to shelf life and packaged product stability. Data from this test method is suitable as a referee method of testing, provided that the purchaser and seller have agreed on sampling procedures, standardization procedures, test conditions, and acceptance criteria.