1.1 本试验方法规定了测定任何建筑材料吸湿吸附等温线的实验室程序。该方法最初是为ASTM绝热委员会开发的。 1.2 对于材料表征，主要重点是吸附等温线（即描述材料在烘箱干燥条件下的润湿过程的吸附等温线）。 1.3 当需要关于建筑材料干燥特性的信息时，进行解吸等温线（即，描述材料从用水绝对饱和状态下的干燥过程的吸附等温线）的确定。 通常，为了湿热模型的目的，需要吸附等温线和解吸等温线。 1.4 以国际单位制表示的数值应视为标准。本标准不包括其他计量单位。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者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。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 4.1 这些试验的目的是通过规定的实验室程序，在规定的温度下，获得不同相对湿度水平下的平衡含水量值。这些值要么被用作表征材料的手段，要么被用作输入适当的计算机模型所需的材料特性，该计算机模型可以模拟特定环境条件下单个建筑材料或材料组件的润湿或干燥潜力。 4.2 平衡含水量的指定值也可以用于材料表征。 如果材料规范中要求这种类型的材料表征（例如，矿物或纤维素纤维绝缘），则95±3时的平衡 %应使用RH。 4.3 为了便于测量和重复性，在吸附等温线上进行表征测量。尽管解吸与吸附相反，但大多数多孔材料在这两个过程中都达到了不同的平衡水平。通常，对于相同水平的RH，解吸等温线上的平衡水分含量高于吸附等温线上的均衡水分含量。

1.1 This test method specifies a laboratory procedure for the determination of hygroscopic sorption isotherms of any construction materials. The method was originally developed for the ASTM Thermal Insulation committee. 1.2 For material characterization, the primary emphasis is on the adsorption isotherm (that is, sorption isotherm that describes the wetting process of the material from the oven-dry condition). 1.3 Determination of desorption isotherm, (that is, sorption isotherm that describes the drying process of a material from the state of absolute saturation with water) is performed when information on drying characteristics of construction materials is required. Typically both adsorption and desorption isotherms are required for the purpose of hygrothermal models. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 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. 1.6 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 ====== 4.1 The purpose of these tests is to obtain, for a specified temperature, by means of a specified laboratory procedure, the values of the equilibrium moisture content at various levels of RH. These values are used either as means to characterize the material or as material characteristics needed as input to appropriate computer models that can simulate wetting or drying potential of individual building materials or material assemblies under specified environmental conditions. 4.2 A specified value of the equilibrium moisture content can also be used for material characterization. If this type of material characterization is called for in a material specification (for example, mineral or cellulose fiber insulation), the equilibrium at 95 ± 3 %RH shall be used. 4.3 For ease and repeatability of measurements, the measurements for characterization are performed on adsorption isotherms. Though desorption is the reverse of adsorption, most porous materials reach different equilibrium levels during these two processes. Usually, the equilibrium moisture content on the desorption isotherm is higher than that on the adsorption isotherm for the same level of RH.