1.1 本试验方法描述了一种精确的技术，用于在1000到1800 K的温度范围内，在1到35μm的波长下测量电绝缘材料的正常光谱发射率。它特别适用于测量陶瓷氧化物等材料的正常光谱发射率，其导热系数相对较低，在表面以下相当深的地方（几毫米）是半透明的，但在厚度为10毫米或更小时基本上是不透明的。 1.2 这种测试方法需要昂贵的设备和相当精细的预防措施，但产生的数据准确度在几%以内。它特别适用于需要最高精度和准确度的研究实验室，不建议用于常规生产或验收测试。由于其高精度，本试验方法可作为参考方法，在发生争议时应用于生产和验收试验。 1.3 该试验方法需要使用特定的试样尺寸和配置，以及特定的加热和观察技术。 关键样品炉的设计细节见Ref( 1. ), 2. 使用这种设计的熔炉是符合本试验方法的必要条件。概述了转移光学和分光光度计。 1.4 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。 1.5 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。 1.6 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 通过对该技术局限性的讨论，突出了其显著特征。根据本试验方法以下部分中给出的描述和安排，仪器将直接记录试样的正常光谱发射度。 但是，必须在可接受的公差范围内满足以下条件，或者必须对指定条件进行纠正。 5.1.1 样品和黑体的有效温度必须在1K以内。然而，由于温度均匀性通常不优于几个开尔文，因此存在实际限制。 5.1.2 两个光束中的光程长度必须相等，或者，最好是仪器应在非吸收大气中运行，以消除两个光束中大气吸收差的影响。 在许多情况下，在空气中进行测量很重要，不一定会得到与在真空中相同的结果，因此双光束仪器的光路均匀性变得非常关键。 注4: 需要对分光光度计进行非常仔细的光学校准，以最大限度地减少仪器两条路径上的吸收率差异，并仔细调整斩波器计时，以减少“串扰”（参考信号和样本信号的重叠），以及采取预防措施，以减少分光光度计中的杂散辐射，以保持零线平坦。 通过最佳调整，“100%线”将平坦到3%以内。 5.1.3 除棱镜单色器中的棱镜外，必须始终使用前表面反射镜光学元件，并且应强调的是，必须在两个光束中使用等效光学元件，以便通过光学元件中的吸收来减少和平衡光束的衰减。建议光学表面不含二氧化硅 2. 和SiO涂层:MgF 2. 可用于长时间稳定镜面。 这些涂层的光学特性至关重要，但如果在测量过程中所有光程固定，或者在操作模式之间（在0%线、100%线和样品测量过程中）入射角不变，则可以放宽这些涂层的光学特性。建议所有光学元件充分充满能量。 5.1.4 两个光束的源孔径和场孔径必须相等，以确保通过该装置比较的两个光束中的辐射通量与源面积相等和发射立体角相等有关。 在某些情况下，在比较替代测量技术时，可能需要定义光源和样品的立体角。 5.1.5 探测器-放大器系统的响应必须随入射辐射通量线性变化，或者必须校准线性，并对观察到的线性偏差进行校正。

1.1 This test method describes an accurate technique for measuring the normal spectral emittance of electrically nonconducting materials in the temperature range from 1000 to 1800 K, and at wavelengths from 1 to 35 μm. It is particularly suitable for measuring the normal spectral emittance of materials such as ceramic oxides, which have relatively low thermal conductivity and are translucent to appreciable depths (several millimetres) below the surface, but which become essentially opaque at thicknesses of 10 mm or less. 1.2 This test method requires expensive equipment and rather elaborate precautions, but produces data that are accurate to within a few percent. It is particularly suitable for research laboratories, where the highest precision and accuracy are desired, and is not recommended for routine production or acceptance testing. Because of its high accuracy, this test method may be used as a reference method to be applied to production and acceptance testing in case of dispute. 1.3 This test method requires the use of a specific specimen size and configuration, and a specific heating and viewing technique. The design details of the critical specimen furnace are presented in Ref ( 1 ), 2 and the use of a furnace of this design is necessary to comply with this test method. The transfer optics and spectrophotometer are discussed in general terms. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 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. 1.6 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 significant features are typified by a discussion of the limitations of the technique. With the description and arrangement given in the following portions of this test method, the instrument will record directly the normal spectral emittance of a specimen. However, the following conditions must be met within acceptable tolerance, or corrections must be made for the specified conditions. 5.1.1 The effective temperatures of the specimen and blackbody must be within 1 K of each other. Practical limitations arise, however, because the temperature uniformities are often not better than a few kelvins. 5.1.2 The optical path length in the two beams must be equal, or, preferably, the instrument should operate in a nonabsorbing atmosphere, in order to eliminate the effects of differential atmospheric absorption in the two beams. Measurements in air are in many cases important, and will not necessarily give the same results as in a vacuum, thus the equality of the optical paths for dual-beam instruments becomes very critical. Note 4: Very careful optical alignment of the spectrophotometer is required to minimize differences in absorptance along the two paths of the instrument, and careful adjustment of the chopper timing to reduce “cross-talk” (the overlap of the reference and sample signals) as well as precautions to reduce stray radiation in the spectrophotometer are required to keep the zero line flat. With the best adjustment, the “100 % line” will be flat to within 3 %. 5.1.3 Front-surface mirror optics must be used throughout, except for the prism in prism monochromators, and it should be emphasized that equivalent optical elements must be used in the two beams in order to reduce and balance attenuation of the beams by absorption in the optical elements. It is recommended that optical surfaces be free of SiO 2 and SiO coatings: MgF 2 may be used to stabilize mirror surfaces for extended periods of time. The optical characteristics of these coatings are critical, but can be relaxed if all optical paths are fixed during measurements or the incident angles are not changed between modes of operation (during 0 % line, 100 % line, and sample measurements). It is recommended that all optical elements be adequately filled with energy. 5.1.4 The source and field apertures of the two beams must be equal in order to ensure that radiant flux in the two beams compared by the apparatus will pertain to equal areas of the sources and equal solid angles of emission. In some cases it may be desirable to define the solid angle of the source and sample when comparing alternative measurement techniques. 5.1.5 The response of the detector-amplifier system must vary linearly with the incident radiant flux, or must be calibrated for linearity, and corrections made for observed deviations from linearity.