1.1 本试验方法涵盖泡沫塑料，泡沫塑料由分离小空腔或细胞的聚合物膜或壁组成。这些电池可以是互连的（开放电池）、非连接的（封闭电池）或这些类型的任何组合。该测试方法确定开放单元的数值。这是一种孔隙度测定，测量材料的可接近细胞体积。剩余体积为闭合单元和单元壁所占体积。由于任何尺寸方便的样本通常通过一些切割操作获得，因此样本制备将打开一部分封闭细胞，并将其作为开放细胞包括在内（见 注释2 ). 1.2 该测试方法对主要为高度开孔材料提供了良好的准确性。由于不考虑样本制备过程中打开的闭合细胞，精度随着闭合细胞含量的增加和细胞大小的增加而降低。 1.3 以国际单位制表示的数值应视为标准。括号中的值仅供参考。 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 4590使用相同的基本原理，但在实验细节上有显著差异。 注2: 附录中描述了两种校正样本制备过程中打开的细胞的程序 X1.1 . 1.5 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 本试验方法旨在用于泡沫塑料的孔隙率直接影响其最终用途的规范中。 例如，对于隔热应用，需要高百分比的封闭电池来防止气体逸出，并促进低导热性。在浮选应用中，高闭孔含量通常会降低吸水率。 5.2 在继续进行本试验方法之前，应参考被测材料的规范。材料规范中涵盖的任何试样制备、调节或尺寸或两者，以及测试参数应优先于本测试方法中提及的参数。如果没有材料规范，则默认条件适用。

1.1 This test method covers cellular plastics, which are composed of membranes or walls of polymer separating small cavities or cells. These cells may be interconnecting (open cell), non-connecting (closed cell), or any combination of these types. This test method determines numerical values for open cells. It is a porosity determination, measuring the accessible cellular volume of a material. The remaining volume is that occupied by closed cells and cell walls. Since any conveniently sized specimen is typically obtained by some cutting operation, a fraction of the closed cells will be opened by specimen preparation and will be included as open cells, (see Note 2 ). 1.2 This test method provides good accuracy on predominantly highly open-celled materials. By not accounting for closed cells that were opened during specimen preparation, the accuracy decreases as the closed cell content increases and as the cell size increases. 1.3 The values as stated in SI units are to be regarded as the standard. The values in parentheses are given for reference only. 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. Note 1: This test method and ISO 4590 use the same basic principles but are significantly different in experimental detail. Note 2: Two procedures for correcting for cells opened during specimen preparation are described in Appendix X1.1 . 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 ====== 5.1 This test method is intended to be used in specifications where porosity of cellular plastics has a direct bearing on their end use. For example, for thermal insulation applications, a high percentage of closed cells is necessary to prevent escape of gases and to promote low thermal conductivity. In flotation applications, high closed-cell content generally reduces water absorption. 5.2 Before proceeding with this test method, reference shall be made to the specification of the material being tested. Any test specimen preparation, conditioning, or dimensions, or both, and testing parameters covered in the materials specification shall take precedence over those mentioned in this test method. If there are no material specifications, then the default conditions apply.