1.1 该量热测试方法包括测定高达1400°C左右的金属和石墨表面以及涂层金属表面的总半球发射率。上限使用温度仅受试样的特性（例如，熔化温度、蒸汽压）和测试设施的设计限制。该测试方法已被证明可在1400年内使用 °C。较低的使用温度受钟形罩温度的限制。 1.2 以国际单位制表示的数值应视为标准值。 本标准不包括其他计量单位。 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。 有关具体的危险说明，请参阅第节 7. . 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====== 5.1 通过本试验方法测量的发射度可用于计算代表试样且在试样温度范围内的表面的辐射热传递。 5.2 该测试方法可用于确定使用条件对材料发射度的影响。特别是，在所有金属绝缘中常用材料的炉暴露（温度下的时间）下使用本试验方法可以确定氧化对发射度的影响。 5.3 本试验方法中所述的测量是在真空环境中进行的。通常，该条件将提供适用于在其他条件下（例如在空气环境中）使用的材料的发射度值。然而，必须认识到，在空气或其他大气中使用的材料的表面特性可能不同。此外，预处理表面，如中所述 5.2 在真空环境中，由于吸收气体的真空剥离和其他相关真空效应，可能会发生变化。 因此，在真空下测量的发射度可能与空气中存在的发射度值不同，用户必须意识到这种情况。考虑到这些条件，通过本试验方法获得的发射度可用于预测热传递。 5.4 如本试验方法所述，在推导发射度计算时作出了一些假设。它们是: 5.4.1 外壳是一个温度均匀的黑体发射器， 5.4.2 在外壳温度下，完全漫射黑体辐射的总半球吸收率等于样品在其温度下的总半球发射率，并且 5.4.3 试验段不会因对流或传导而产生热损失。对于通过本测试方法中所述程序测试的大多数材料，这些假设的影响很小，要么被忽略，要么对测量的发射度进行校正。 5.5 为了获得符合本试验方法的满意结果，应遵循本试验方法中描述的仪器的尺寸、结构和使用原则。如果遵循这些原则，通过使用本试验方法获得的任何测量值预计将精确到±5以内 %. 如果报告结果是通过本试验方法获得的，则应满足本试验方法中规定的所有要求。 5.6 在这种类型的测试方法中，确定结构和程序的细节以涵盖可能给不具备传热理论、温度测量和一般测试实践相关技术知识的人带来困难的所有意外情况是不现实的。本试验方法的标准化并不会减少对此类技术知识的需求。 人们还认识到，由于这种测试方法的标准化，以任何方式限制研究人员开发改进的或新的方法或程序是不明智的。

1.1 This calorimetric test method covers the determination of total hemispherical emittance of metal and graphite surfaces and coated metal surfaces up to approximately 1400°C. The upper-use temperature is limited only by the characteristics (for example, melting temperature, vapor pressure) of the specimen and the design limits of the test facility. This test method has been demonstrated for use up to 1400 °C. The lower-use temperature is limited by the temperature of the bell jar. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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. For specific hazard statements, see Section 7 . 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 ====== 5.1 The emittance as measured by this test method can be used in the calculation of radiant heat transfer from surfaces that are representative of the tested specimens, and that are within the temperature range of the tested specimens. 5.2 This test method can be used to determine the effect of service conditions on the emittance of materials. In particular, the use of this test method with furnace exposure (time at temperature) of the materials commonly used in all-metallic insulations can determine the effects of oxidation on emittance. 5.3 The measurements described in this test method are conducted in a vacuum environment. Usually this condition will provide emittance values that are applicable to materials used under other conditions, such as in an air environment. However, it must be recognized that surface properties of materials used in air or other atmospheres may be different. In addition, preconditioned surfaces, as described in 5.2 , may be altered in a vacuum environment because of vacuum stripping of absorbed gases and other associated vacuum effects. Thus, emittances measured under vacuum may have values that differ from those that exist in air, and the user must be aware of this situation. With these qualifications in mind, emittance obtained by this test method may be applied to predictions of thermal transference. 5.4 Several assumptions are made in the derivation of the emittance calculation as described in this test method. They are that: 5.4.1 The enclosure is a blackbody emitter at a uniform temperature, 5.4.2 The total hemispherical absorptance of the completely diffuse blackbody radiation at the temperature of the enclosure is equal to the total hemispherical emittance of the specimen at its temperature, and 5.4.3 There is no heat loss from the test section by convection or conduction. For most materials tested by the procedures as described in this test method, the effects of these assumptions are small and either neglected or corrections are made to the measured emittance. 5.5 For satisfactory results in conformance with this test method, the principles governing the size, construction, and use of apparatus described in this test method should be followed. If these principles are followed, any measured value obtained by the use of this test method is expected to be accurate to within ±5 %. If the results are to be reported as having been obtained by this test method, all of the requirements prescribed in this test method shall be met. 5.6 It is not practical in a test method of this type to establish details of construction and procedure to cover all contingencies that might offer difficulties to a person without technical knowledge concerning the theory of heat transfer, temperature measurements, and general testing practices. Standardization of this test method does not reduce the need for such technical knowledge. It is recognized also that it would be unwise to restrict in any way the development of improved or new methods or procedures by research workers because of standardization of this test method.