1.1 本试验方法涵盖了在平板或曲面板形式的单相Fickian固体材料的整个厚度方向上测定吸湿或解吸性能的程序。还包括在其他试验方法中使用之前调节试样的程序；达到基本无水分状态，在标准实验室大气环境中达到平衡，或在非实验室环境中达到平衡。还包括用于确定高温试验期间的水分损失的程序，以及从调节环境中移除后由于热暴露而导致的水分损失，例如在应变计粘接期间。 虽然这些程序主要用于层压聚合物基复合材料，但也适用于满足以下假设的其他材料: 1.2 . 1.2 程序A中的全厚度水分扩散系数常数的计算假设单相菲克材料在整个试样厚度内具有恒定的吸湿性能。在试验之前，程序A中用于评估具有先前未知吸湿行为的材料中的水分扩散常数的方程的有效性是不确定的，因为试验结果本身决定了材料是否遵循单一- 相位Fickian扩散模型。在低于其玻璃化转变温度下测试的增强聚合物基复合材料通常满足这一要求，尽管两相基质（如增韧环氧树脂）可能需要多相吸湿模型。虽然试验程序本身可用于多相材料，但程序A中用于确定水分扩散常数的计算仅适用于单相材料。第节讨论了可能不符合要求的其他材料和试验条件示例 6. . 1.3 通过程序A对水分平衡含量材料特性的评估不假设，因此不限于单相Fickian扩散行为。 1.4 可通过适当的自动设备执行本试验方法使用的程序，并减少产生的数据。 1.5 该试验方法符合CMH-17 G版的建议 ( 1. ) , 2. 描述了调节和水分特性测定程序的理想属性。 1.6 以国际单位制或英寸表示的数值- 磅单位应单独视为标准单位。每个系统中规定的值不一定是精确的等价物；因此，为确保符合本标准，每个系统应独立使用，且两个系统的值不得组合。 1.6.1 在文本中，英寸-磅单位显示在括号中。 1.7 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、健康和环境实践，并确定监管限制的适用性。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 程序A旨在产生水分扩散材料特性数据，可按如下方式使用: 5.1.1 确定程序B中优惠券调节的近似暴露时间- E、 Y和Z； 5.1.2 作为水分预测分析计算机代码的输入；或 5.1.3 用于在暴露于各种形式水分的环境中对材料选择或性能作出定性决定。 5.2 程序B-E旨在在其他材料性能测试（包括但不限于机械测试）之前，将试样调节到指定的环境条件或平衡状态。 5.3 程序Y-Z旨在确定由于从调节室中取出试样（例如用于应变计粘接）或由于在机械加载之前和期间加热试样而导致的含水量损失。 5.4 使用程序A对薄和厚试样进行的一对测试提供了水分扩散常数， D z ，以及水分平衡含量， M m ，在给定的湿度暴露水平和温度下。需要在不同温度下进行多次试验，以确定 D z 在温度上。需要在不同的湿度暴露水平下进行多次测试，以确定 M m 湿度暴露水平。 注1: 对于许多聚合物基复合材料，水分扩散率通常仅与相对湿度弱相关，并且通常假设仅与温度有关，通常遵循阿累尼乌斯定律- 与逆绝对温度呈指数关系。对于许多此类材料，水分平衡含量仅与温度弱相关，通常假设仅为相对湿度的函数 ( 1. ) . 5.5 当在用环境条件为蒸汽（如潮湿空气）时，应使用蒸汽暴露试验来调节样品。只有在以下情况下，才应使用浸入液浴来模拟蒸汽暴露 显然的 出于定性目的，需要吸收特性。以后一种方式确定的特性应报告为: 显然的 属性。 注2: 对于许多聚合物基复合材料，在大气潮湿条件下的吸湿性能通常不等同于暴露在液体浸泡或加压蒸汽中。后一种环境可能具有不同的材料扩散特性。

1.1 This test method covers a procedure for the determination of moisture absorption or desorption properties in the through-the-thickness direction for single-phase Fickian solid materials in flat or curved panel form. Also covered are procedures for conditioning test coupons prior to use in other test methods; either to an essentially moisture-free state, to equilibrium in a standard laboratory atmosphere environment, or to equilibrium in a non-laboratory environment. Also included are procedures for determining the moisture loss during elevated temperature testing, as well as moisture loss resulting from thermal exposure after removal from the conditioning environment, such as during strain gauge bonding. While intended primarily for laminated polymer matrix composite materials, these procedures are also applicable to other materials that satisfy the assumptions of 1.2 . 1.2 The calculation of the through-the-thickness moisture diffusivity constant in Procedure A assumes a single-phase Fickian material with constant moisture absorption properties through the thickness of the specimen. The validity of the equations used in Procedure A for evaluating the moisture diffusivity constant in a material of previously unknown moisture absorption behavior is uncertain prior to the test, as the test results themselves determine if the material follows the single-phase Fickian diffusion model. A reinforced polymer matrix composite material tested below its glass-transition temperature typically meets this requirement, although two-phase matrices such as toughened epoxies may require a multi-phase moisture absorption model. While the test procedures themselves may be used for multi-phase materials, the calculations used to determine the moisture diffusivity constant in Procedure A are applicable only to single-phase materials. Other examples of materials and test conditions that may not meet the requirements are discussed in Section 6 . 1.3 The evaluation by Procedure A of the moisture equilibrium content material property does not assume, and is therefore not limited to, single-phase Fickian diffusion behavior. 1.4 The procedures used by this test method may be performed, and the resulting data reduced, by suitable automatic equipment. 1.5 This test method is consistent with the recommendations of CMH-17 Rev G ( 1 ) , 2 which describes the desirable attributes of a conditioning and moisture property determination procedure. 1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.6.1 Within the text, the inch-pound units are shown in brackets. 1.7 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 Procedure A is designed to produce moisture diffusion material property data that may be used as follows: 5.1.1 To determine approximate exposure times for coupon conditioning in Procedures B-E, Y, and Z; 5.1.2 As input to moisture prediction analysis computer codes; or 5.1.3 For making qualitative decisions on material selection or performance under environmental exposure to various forms of moisture. 5.2 Procedures B-E are designed to condition test coupons to a specified environmental condition or equilibrium state prior to other material property testing (including, but not limited to, mechanical testing). 5.3 Procedures Y-Z are designed to determine the loss of moisture content due to removal of a test coupon from the conditioning chamber (such as for strain gauge bonding) or due to heating of the test coupon prior to and during mechanical loading. 5.4 A single pair of tests on thin and thick specimens using Procedure A provides the moisture diffusivity constant, D z , and the moisture equilibrium content, M m , at the given moisture exposure level and temperature. Multiple tests at differing temperatures are required to establish the dependence of D z on temperature. Multiple tests at differing moisture exposure levels are required to establish the dependence of M m on moisture exposure level. Note 1: For many polymer matrix composites, the moisture diffusivity is usually only weakly related to relative humidity and is often assumed to be a function only of temperature, usually following an Arrhenius-type exponential relation with inverse absolute temperature. For many of these materials, moisture equilibrium content is only weakly related to temperature and is usually assumed to be a function only of relative humidity ( 1 ) . 5.5 Vapor-exposure testing shall be used to condition the specimen when the in-service environmental condition is a vapor such as humid air. Immersion in a liquid bath should be used to simulate vapor exposure only when apparent absorption properties are desired for qualitative purposes. Properties determined in the latter manner shall be reported as apparent properties. Note 2: For many polymer matrix composites, the moisture absorption properties under atmospheric humid conditions are generally not equivalent to exposure either to liquid immersion or to pressurized steam. These latter environments may have different material diffusion characteristics.