1.1 本试验方法适用于预制或现场制造的隔热产品，如板材泡沫、硬质纤维和复合材料，无论是否带有保护面。看见 注1 . 本试验方法不适用于高温、反射或松散填充绝缘。 注1: 如果产品是用刮刀制造的，则在刮刀就位的情况下测试产品。 1.2 该试验方法包括两个阶段:预处理和环境循环。在第一阶段，25毫米（1英寸）厚试样用于分离两种环境。每种环境都有恒定但不同的温度和湿度水平。在环境循环阶段，试样还分为两个环境，即一侧的恒定室温/湿度和另一侧的循环温度/环境相对湿度。 1.3 本试验方法测量产品在标准暴露条件下保持热性能和关键物理属性的能力。比较了在试验期间储存在实验室的参考试样和采用两阶段试验方法的试样的材料性能。为了消除比较中的水分影响，在干燥至恒重后测定后一种试样的材料性能。使用为两组样本中的每一组确定的平均值进行比较。 1.4 可以测量不同的性能，以评估环境因素对隔热的影响。 本试验方法要求根据完成试验后测量的三个试样的平均值来确定热阻。本试验方法的次要元素包括目视观察，如开裂、分层或其他表面缺陷，以及试验方法规定的两个暴露阶段中的每个阶段后的含水量变化。 1.5 测试材料的特性是本测试方法的一个基本要素。用于表征的材料特性将包括抗压强度或抗拉强度值。在两组试样上测量抗压强度或抗拉强度，其中一组按 1.2 以及从同一批材料中提取的一组参考试样，并在整个试验期间储存在实验室中。 为了进行比较，确定了两组试样的平均值。 1.6 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 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 将试样暴露在单向环境循环的条件下可以增加其含水量，直到材料性能下降（在特定的循环次数下）。由于导致材料性能下降所需的循环次数，此类测试可能不合适，因为产品性能问题通常只有在暴露多年后才会出现。预处理程序的使用并不是为了复制预期的现场性能。相反，其目的是在进行环境循环之前增加试验材料的含水量。 5.2 预处理程序最重要的方面是非- 试样中均匀的水分分布。热流是单向的，导致水分流向冷侧，导致热侧出现干燥材料区域，冷侧出现高含水量。（高含水量区是位于试样的冷表面上，还是与该表面保持一定距离，取决于温度振荡和冷表面向外干燥的能力）。由于预处理程序涉及热梯度，该预处理程序导致在现场暴露条件下可能出现的含水量分布。然而，由此产生的含水量可能与典型产品应用中显示的含水量存在显著差异。 5.3 预处理会导致由于同时暴露在温差和水蒸汽压下而在隔热层中积聚水分。本试验方法无意重复现场暴露。它旨在提供比较评级。由于施工系统中水分的过度累积可能会对其性能产生不利影响，设计师应考虑水分累积的可能性以及水分对系统性能的可能影响。

1.1 This test method is applicable to preformed or field manufactured thermal insulation products, such as board stock foams, rigid fibrous and composite materials manufactured with or without protective facings. See Note 1 . This test method is not applicable to high temperature, reflective or loose fill insulation. Note 1: If the product is manufactured with a facer, test product with facer in place. 1.2 This test method involves two stages: preconditioning and environmental cycling. During the first stage, 25 mm (1 in.) thick specimens are used to separate two environments. Each of these environments has a constant but different temperature and humidity level. During the environmental cycling stage, specimens also divide two environments namely constant room temperature/humidity on one side and cycling temperature/ambient relative humidity on the other side. 1.3 This test method measures the ability of the product to maintain thermal performance and critical physical attributes after being subjected to standardized exposure conditions. A comparison is made between material properties for reference specimens stored in the laboratory for the test period and specimens subjected to the two-stage test method. To eliminate the effect of moisture from the comparison, the material properties of the latter test specimens are determined after they have been dried to constant weight. The average value determined for each of the two sets of specimens is used for comparison. 1.4 Different properties can be measured to assess the effect of environmental factors on thermal insulation. This test method requires that thermal resistance be determined based upon an average for three specimens measured after completing the test. Secondary elements of this test method include visual observations such as cracking, delamination or other surface defects, as well as the change in moisture content after each of the two stages of exposure prescribed by the test method. 1.5 Characterization of the tested material is an essential element of this test method. Material properties used for characterization will include either compressive resistance or tensile strength values. The compressive resistance or tensile strength is measured on two sets of specimens, one set conditioned as defined in 1.2 and a set of reference test specimens taken from the same material batch and stored in the laboratory for the whole test period. For comparison, an average value is determined for each of the two sets of specimens. 1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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 Exposing a specimen to conditions of one-directional environmental cycling can increase its moisture content until a decrease in material properties occurs (at a specific number of cycles). Such a test could be inappropriate due to the number of cycles required to cause a decrease in material properties since product performance issues often arise only after many years of exposure. The use of a preconditioning procedure is not intended to duplicate expected field performance. Rather the purpose is to increase the moisture content of test materials prior to subjecting to them to environmental cycling. 5.2 The most important aspect of the preconditioning procedure is non-uniform moisture distribution in the specimen. The heat flow is one directional causing moisture flow towards the cold side resulting in zones of dry material on the warm side and high moisture content on the cold side. (Whether the high moisture content zone is located right at the cold surface of the specimen or at some distance from this surface depends upon temperature oscillation and ability of the cold surface to dry outwards). Because the preconditioning procedure involves thermal gradient, this preconditioning procedure results in a distribution of moisture content that may occur under field exposure conditions. However, the resulting moisture content may differ significantly from that which may be demonstrated in typical product applications. 5.3 The preconditioning results in accumulation of moisture in the thermal insulation resulting from the simultaneous exposure to a difference in temperature and water vapor pressure. This test method is not intended to duplicate field exposure. It is intended to provide comparative ratings. As excessive accumulation of moisture in a construction system may adversely affect its performance, the designer should consider the potential for moisture accumulation and the possible effects of this moisture on the system performance.