1.1 该测试方法描述了用于测定厚度小于25mm的材料的热传递阻力(热阻)的稳态技术。可以测定均匀不透明固体样品的热导率（参见 附注1 ).该测试方法特别适用于热阻范围为10(cm)的均质、多层和复合试样。 2 ·K·W -1 至400(cm) 2 ·K·W -1 其可以从具有大约0.1 W·m的热导率范围的材料获得 -1 ·K -1 至30 W·m -1 ·K -1 在大约150 K到600 K的温度范围内。对于较厚的样品和高达60 W·m的热导率值，它可以在这些范围之外使用，但精度降低 -1 ·K -1 . 附注1: 当发现待测量的特性与样品尺寸无关时，物体被认为是均匀的。1.2 该试验方法在概念上与试验方法相似 C518 但被修改以适应具有较高热导率的较小测试样本。此外，已经非常注意确保接触表面的热阻最小化和可再现。 1.3 以SI单位表示的值将被视为标准值。本标准不包括其他计量单位。 1.4 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践并确定法规限制的适用性。 1.5 本国际标准是根据世界贸易组织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技术性贸易壁垒委员会。 ======意义和用途====== 5.1 本试验方法描述了在受控条件下测量和比较试样（厚度小于25 mm）热阻特性的程序。

1.1 This test method describes a steady-state technique for the determination of the resistance to thermal transmission (thermal resistance) of materials having a thickness of less than 25 mm. Thermal conductivity may be determined for homogeneous opaque solid specimens (see Note 1 ). This test method is particularly useful for homogeneous, multilayer, and composite specimens having a thermal resistance in the range from 10 (cm) 2 ·K·W -1 to 400 (cm) 2 ·K·W -1 , which may be obtained from materials with an approximate thermal conductivity range 0.1 W·m -1 ·K -1 to 30 W·m -1 ·K -1 over the approximate temperature range from 150 K to 600 K. It can be used outside these ranges with reduced accuracy for thicker specimens and for thermal conductivity values up to 60 W·m -1 ·K -1 . Note 1: A body is considered homogeneous when the property to be measured is found to be independent of specimen dimensions. 1.2 This test method is similar in concept to Test Method C518 , but is modified to accommodate smaller test specimens, having a higher thermal conductance. In addition, significant attention has been paid to ensure that the thermal resistance of contacting surfaces is minimized and reproducible. 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 ====== 5.1 This test method describes a procedure to measure and compare the thermal resistance properties of specimens (less than 25 mm in thickness) under controlled conditions.