1.1 本试验方法包括一种筛选型质量控制试验，用于确定软质聚氨酯泡沫垫是否在规定的硬度等级范围内。 1.2 本试验方法仅限于厚度为75 mm[3 in]或更大的泡沫。 1.3 本试验方法基于以下事实:压痕力挠度（IFD）的传统行业标准厚度为100 mm[4 in.]，而IFD验收和产品规划的传统挠度百分比为25% %. 那么，就这些传统行业惯例而言，25 % 100°上的挠度- 毫米[4英寸]的缓冲垫为25毫米[1英寸]。因此，偏转标准垫层（适当的100 mm厚度）25 mm[1 in]提供了一种快速方法，以确定柔性聚氨酯泡沫是否在25的规定等级范围内 % IFD。 1.4 不应使用本试验方法对厚度小于75 mm[3 in]的垫层进行IFD试验。 1.5 本试验方法旨在提供一种快速、简单的方法来筛选软质聚氨酯泡沫，以测定其硬度等级。 1.6 单位- 以美国惯用或国际单位制表示的数值应单独视为标准。 每个系统中规定的值可能不是精确的等效值；因此，每个系统应相互独立使用。将两个系统的值合并可能会导致不符合标准。 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。 注1: 本试验方法和ISO 2439涉及相同的主题，但技术内容不同。 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====== 4.1 建议使用25毫米[1英寸]偏转IFD方法仅对全尺寸座垫进行生产筛选和质量控制。 4.2 用本试验方法测试的适用垫层厚度仅为本试验方法中列出的厚度。 在该试验方法适用于其他垫层厚度之前，需要进一步研究和开发。 4.3 该测试方法旨在给出一个近似于25的值 % 当测试的实际试样厚度在测试方法中列出的范围内时，在100 mm[4英寸]厚的泡沫上进行IFD。如有分歧，仲裁方法为测试方法中的IFD程序 D3574 ，测试B 1. .本试验方法的使用者应建立本试验方法和仲裁方法之间的相关性。

1.1 This test method covers a screening type quality control test used to determine if flexible polyurethane foam cushions are within the specified grade range for firmness. 1.2 This test method is limited to foams with thicknesses that are 75 mm [3 in.] or greater. 1.3 This test method is based on the fact that the traditional industry standard thickness for Indentation Force Deflection (IFD) is 100 mm [4 in.], and the traditional percent deflection for IFD acceptance and product planning is 25 %. With respect, then, to these traditional industry conventions, a 25 % deflection on a 100-mm [4-in.] cushion would be 25 mm [1 in.]. Thus, deflecting standard cushions (of proper 100 mm thickness) 25 mm [1 in.] provides a quick way to determine if the flexible polyurethane foam is within the specified grade range for 25 % IFD. 1.4 Cushion thicknesses less than 75 mm [3 in.] shall not be tested for IFD using this test method. 1.5 This test method is intended to provide a quick and simple method to screen flexible polyurethane foams for determination of its firmness grade. 1.6 Units— The values stated in U.S. Customary or SI units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the 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. Note 1: This test method and ISO 2439 address the same subject matter, but differ in technical content. 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 ====== 4.1 The 25-mm [1-in.] deflection IFD method is recommended for production screening and quality control on full size cushions only. 4.2 Applicable cushion thicknesses to be tested by this test method are only those listed in this test method. Further research and development are required before this test method is applicable to other cushion thicknesses. 4.3 This test method is designed to give a value approximating the 25 % IFD on a 100-mm [4-in.] thick piece of foam when the actual specimen thickness tested is within the ranges listed in the test method. In case of disagreement, the referee method is the IFD procedure in Test Methods D3574 , Test B 1 . The user of this test method shall establish the correlation between this test method and the referee method.