1.1 本试验方法涵盖了非刚性热塑性片材或薄膜线性尺寸变化的测量，这些变化是由于材料暴露在规定的高温和时间条件下引起的。 1.2 以国际单位制表示的数值应视为标准。 1.3 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 国际标准化组织 11501 解决相同的问题，但技术内容不同（两种方法之间的结果无法直接比较）。 1.4 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 本试验方法特别适用于通过压延或挤压工艺制成的非刚性热塑性片材或薄膜。该测试表明，在加工过程中引入的内部应变程度方面，批次之间的一致性。 4.2 本试验方法中的加热介质为空气，不一定产生与试验方法相同的结果 D2732 ，它使用液体介质。 4.3 在继续使用本试验方法之前，请查看被测材料的规格（如果可用）。相关ASTM材料规范中涵盖的任何试样制备、调节、尺寸或测试参数，或其组合，应优先于本试验方法中提及的。如果没有相关的ASTM材料规范，则默认条件适用。分类系统表1 D4000 列出了当前存在的ASTM材料标准。

1.1 This test method covers the measurement of changes in linear dimensions of nonrigid thermoplastic sheeting or film that result from exposure of the material to specified conditions of elevated temperature and time. 1.2 The values stated in SI units are to be regarded as the standard. 1.3 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 11501 address the same matter, but differ in technical content (and results cannot be directly compared between the two methods). 1.4 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 This test method is particularly applicable to nonrigid thermoplastic sheeting or film made by the calender or extrusion process. The test gives an indication of lot-to-lot uniformity in regards to the degree of internal strains introduced during processing. 4.2 The heating medium in this test method is air and does not necessarily yield the same results as Test Method D2732 , which uses a liquid medium. 4.3 Before proceeding with this test method, review the specifications of the material being tested, if available. Any test specimen preparation, conditioning, dimensions, or testing parameters, or combination thereof, covered in the relevant ASTM material specification shall take precedence over those mentioned in this test method. If there are no relevant ASTM material specifications, then the default conditions apply. Table 1 of Classification System D4000 lists the ASTM material standards that currently exist.