1.1 本规程描述了用仪器测定回复反射器的回复反射色度坐标。它包括在光度范围内使用的技术，用于使用远比色计或远分光辐射计测量反向反射（夜间）色度。 1.2 本规程涵盖了一般测量程序。具体测试和规范的附加要求见第节 7. . 1.3 在实践中描述了用于回复反射器夜间色度测定的几何形状 E808 色度的计算方法包含在实践中 E308年 . 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====== 5.1 本规程描述了夜间测量回复反射器色度的程序，即回复反射、照明几何和观察。 已选择CIE标准光源A代表钨汽车前照灯。尽管几何形状必须由本实施规程的用户指定，但通常它将对应于车辆前照灯、回复反射器和车辆驾驶员眼睛之间的关系。因此，由本实施例中的程序确定的色度坐标在数值上描述了回复反射器的夜间外观。

1.1 This practice describes the instrumental determination of retroreflected chromaticity coordinates of retroreflectors. It includes the techniques used in a photometric range to measure retroreflected (nighttime) chromaticity with either a telecolorimeter or telespectroradiometer. 1.2 This practice covers the general measurement procedures. Additional requirements for specific tests and specifications are described in Section 7 . 1.3 The description of the geometry used in the nighttime colorimetry of retroreflectors is described in Practice E808 and the methods for calculation of chromaticity are contained in Practice E308 . 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 practice describes a procedure for measuring the chromaticity of retroreflectors in a nighttime, that is, retroreflective, geometry of illumination and observation. CIE Standard Source A has been chosen to represent a tungsten automobile headlamp. Although the geometry must be specified by the user of this practice, it will, in general, correspond to the relationship between the vehicle headlamp, the retroreflector, and the vehicle driver's eyes. Thus, the chromaticity coordinates determined by the procedures in this practice describe numerically the nighttime appearance of the retroreflector.