1.1 本试验方法规定了在极高相对湿度（RH）水平下测定多孔建筑材料保水曲线（或储湿能力）的实验室程序( ≈ 95至100%RH），对应于吸附等温线的毛细管水分区域。这是通过使用压力板测试设备来实现的。这项技术最初是为了研究土壤含水量而开发的，最终被应用于建筑材料。 1.2 在较高的RH水平下( ≈ 95至100%RH）（见试验方法 1949年 )，不能选择使用气候室。该技术使用超压将水从多孔材料的孔隙结构中提取出来，直到试样中的水分含量和相应的超压之间达到平衡。使用压力板提取器，只有通过解吸才能达到平衡。 1.3 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。 1.4 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。 1.5 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 本试验的目的是通过指定的实验室程序，获得较高RH水平下的平衡含水量值(( ≈ 95%至100%）。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。

1.1 This test method specifies a laboratory procedure for the determination of the water retention curve (or moisture storage capacity) of porous building materials at very high relative humidity (RH) levels ( ≈ 95 to 100% RH) corresponding to the capillary moisture region of the sorption isotherm. This is achieved by using the pressure plate test apparatus. This technique was originally developed to study soil moisture content and eventually had been adapted to building construction materials. 1.2 At higher RH levels ( ≈ 95 to 100% RH) of the sorption isotherm (see Test Method C1498 ), use of climatic chamber is not an option. This technique uses overpressure to extract water out of the pore structure of porous materials until equilibrium between the moisture content in the specimens and the corresponding overpressure is achieved. Using the pressure plate extractors, equilibrium can only be reached by desorption. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 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. 1.5 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 this test is to obtain, by means of a specified laboratory procedure, the values of the equilibrium moisture content at higher RH levels (( ≈ 95 to 100%). 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.