1.1 这些试验方法包括测定预制建筑隔音砖或铺设在天花板上的强度特性，如下所示: 测验 小节 硬度 4. 到 9 易碎性 10 到 16 下垂 17 到 23 横向强度 24 到 30 1.2 并非这些测试方法中描述的所有测试都是评估特定用途的任何特定产品所必需的。在每种情况下，都需要确定需要哪些属性。 1.3 这些测试方法规定了产品开发、制造控制、规范验收和服务评估中使用的程序。 1.4 这些试验方法确定的性能反映了材料在特定试验条件下的性能，不一定表示在本文规定以外的条件下的性能。 1.5 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。 每个系统中规定的值不是精确的等价物；因此，每个系统应相互独立使用。将两个系统的值合并将导致不符合标准。 1.6 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。 1.7 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====== 4.1 硬度知识有助于隔音砖和铺设的开发和质量控制- 天花板中。偏离既定硬度范围将有助于指出加工误差或有缺陷的原材料，从而有助于保持产品质量的一致性。 4.2 该特性在比较材料抵抗冲击引起的面板表面凹痕的相对能力时也很有用。 4.3 由于硬度随厚度变化，只能直接比较相同厚度的样品。

1.1 These test methods cover the determination of the strength properties of prefabricated architectural acoustical tile or lay-in ceiling panels as follows: Tests Sections Hardness 4 to 9 Friability 10 to 16 Sag 17 to 23 Transverse strength 24 to 30 1.2 Not all of the tests described in these test methods are necessary to evaluate any particular product for a specific use. In each instance, it is necessary to determine which properties are required. 1.3 These test methods specify procedures that are used in product development, manufacturing control, specification acceptance, and service evaluation. 1.4 Properties determined by these test methods reflect the performance of the materials under the specific conditions of the test, and do not necessarily indicate performance under conditions other than those specified herein. 1.5 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 exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems will result in non-conformance with the standard. 1.6 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. 1.7 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 Knowledge of hardness is useful in the development and the quality control of acoustical tile and lay-in ceiling panels. Deviation from an established hardness range will assist in pointing out processing errors or defective raw materials, thereby aiding the maintenance of uniform product quality. 4.2 This property is also useful in comparing the relative abilities of materials to resist indentations on the panel surface caused by impacts. 4.3 Since the hardness varies with the thickness, only samples of the same thickness shall be directly compared.