本文件计算平均亮度的方法包括各种底部开口以及平透镜和落地透镜单元，包括发光区域中有多个开口的单元。感兴趣的坎德拉值是通过IES相对或绝对光度测量技术获得的，而不是通过应用中的现场测量获得的。该计算仅基于通过灯具角度测量和发光投影面积获得的坎德拉值。本文件涵盖了灯具光度测定现行标准适用的所有光源。其中包括白炽灯、荧光灯、高强度放电（HID）、低压钠和LED光源。

This document's methods of calculating average luminance cover various open-bottom apertures as well as flat- and drop-lensed units, including those with multiple openings in the light emitting area. The candela values of interest are obtained by means of IES techniques for relative or absolute photometry, and are not obtained from field measurements in application. This calculation is based solely on the candela values obtained by goniometric measurement of the luminaire and the luminous projected area. All light sources for which there are current standards for luminaire photometry are covered by this document. These include incandescent, fluorescent, high intensity discharge (HID), low pressure sodium, and LED sources.