1.1 本试验方法涵盖了瞬态热线液体导热法和相关设备（系统）的使用，用于测定水性发动机冷却液、非水性发动机冷却液和相关液体的导热系数、热扩散率和体积热容。该系统拟用于实验室。 1.2 该系统直接测量热导率和热扩散率，无需输入任何其他属性。体积热容是通过将热导率除以所测样品的热扩散率来计算的。 1.3 本试验方法适用于导热系数在0.1至1.0 W/m范围内的任何含水或非含水发动机冷却液或相关流体∙K 1.4 本试验方法不包括与铂发生反应的液体。 1.5 适用于本试验方法的温度范围为-20至100 °C。 1.6 本试验方法需要约40 mL的样品。 1.7 对于在试验温度下蒸汽压为33.8 kPa（4.9 psia）或更低的任何流体，可在无外部加压的情况下使用该系统。 1.8 对于在试验温度下蒸汽压大于33.8 kPa（4.9 psia）的流体，需要外部加压（见 附件A2 ). 1.9 以国际单位制表示的数值应视为标准值。国际单位制后括号中给出的值仅供参考，不被视为标准值。 1.10 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。 1.11 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 本试验方法涵盖发动机冷却液（水或非水）和相关液体的热性能测量。 5.2 在每次测量中，直接测量热导率（λ）和热扩散率（α），体积热容（VHC）由以下关系确定: 5.3 该测试方法是瞬态的，只需要少量样本和短时间（0.8秒）即可进行测量。这些属性使液体中的热对流最小化。 5.4 向传感器导线短暂施加电流只会给试样增加很少的热量，每隔30秒可进行十次重复试验，而不会引起任何明显的对流或温度漂移。

1.1 This test method covers the use of a transient hot wire liquid thermal conductivity method and associated equipment (the System) for the determination of thermal conductivity, thermal diffusivity and volumetric heat capacity of aqueous engine coolants, non-aqueous engine coolants, and related fluids. The System is intended for use in a laboratory. 1.2 The System directly measures thermal conductivity and thermal diffusivity without the requirement to input any additional properties. Volumetric heat capacity is calculated by dividing the thermal conductivity by the thermal diffusivity of the sample measured. 1.3 This test method can be applied to any aqueous or non-aqueous engine coolants or related fluid with thermal conductivity in the range of 0.1 to 1.0 W/m∙K. 1.4 This test method excludes fluids that react with platinum. 1.5 The range of temperatures applicable to this test method is –20 to 100 °C. 1.6 This test method requires a sample of approximately 40 mL. 1.7 The System may be used without external pressurization for any fluid having a vapor pressure of 33.8 kPa (4.9 psia) or less at the test temperature. 1.8 For a fluid having a vapor pressure greater than 33.8 kPa (4.9 psia) at the test temperature, external pressurization is required (see Annex A2 ). 1.9 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 1.10 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. 1.11 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 covers the measurement of thermal properties for engine coolants (aqueous or non-aqueous) and related fluids. 5.2 With each single measurement, the thermal conductivity (λ) and thermal diffusivity (α) are measured directly, and volumetric heat capacity (VHC) is determined by the relationship: 5.3 The test method is transient and requires only a small amount of specimen and a short duration of time (0.8 s) to run a measurement. These attributes minimize heat convection in the liquid. 5.4 The brief application of current to the sensor wire adds very little heat to the test specimen and ten repetitive tests may be applied at 30 s intervals without causing any significant convection or temperature drift.