1.1 本试验方法涵盖了测量透明材料（以下称为试样）反射率的程序。结果可重复，无需指定仪器的特定品牌名称。 1.2 本试验方法适用于基本平坦的零件。如果被测量的零件不是大致平坦的，则可能会出现测量误差。 1.3 单位- 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。 1.4 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。 1.5 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 仪表灯和其他驾驶舱物体的飞机透明度反射一直是许多飞行员关注的问题。由于缺乏可重复的测量方法和反射测量仪器的差异，减少这些反射的尝试受到阻碍。 4.2 本试验方法通过标准化光源、计算方法和被测样品表面面积来减少仪器变化； 未指定仪器品牌。由于反射率定义为两个亮度测量的比率，并且不依赖于绝对测量，因此减少了对测量仪器校准精度的依赖。 4.3 该测试方法可用于客观比较各种透明材料的反射特性。此外，通过使用指定光谱分布光源（例如单色发光二极管）代替标准光源，可以使用该测试方法来评估该光源的反射。 4.4 规定检查样品的偏振效应，并记录标准样品的反射率。这些规定作为测试人员的选项提供； 由用户或要求机构确定这些数据的重要性和用途。 4.5 由于反射是通过光学测量的，因此结果代表了飞行员的视觉感知。

1.1 This test method covers a procedure for measuring the reflectivity of transparent materials, hereafter known as specimens. The results are repeatable without specifying a particular brand name of instrumentation. 1.2 This test method applies to substantially flat parts. Errors in measurement can occur if the parts being measured are not substantially flat. 1.3 Units— 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 ====== 4.1 Reflections from aircraft transparencies of instrument lights and other cockpit objects have been a concern to many pilots. Attempts to reduce these reflections have been hampered by the lack of a repeatable measurement method and variances in reflection measuring instrumentation. 4.2 This test method reduces the instrument variations by standardizing the light source, calculation method, and area of specimen surface being measured; a brand of instrumentation is not specified. Since the reflectivity is defined as the ratio of two luminance measurements and does not depend on an absolute measurement, dependence upon the accuracy of the calibration of the measuring instrument is reduced. 4.3 The test method may be used to objectively compare the reflection characteristics of various transparent materials. Furthermore, the test method may be used to evaluate reflections of a specified spectral distribution light source (for example, a monochromatic light-emitting diode) by using that source in place of the standard light source. 4.4 Provisions are made to check for polarization effects of the sample and to record the reflectivity of a standard specimen. These provisions are offered as an option to the tester; it is up to the user or the requiring agency to determine the significance and use of these data. 4.5 Since the reflections are measured photopically, the results are representative of what the pilot would visually perceive.