本报告给出在实际户外照明应用中一致实施国际照明委员会中间视觉光度系统（CIE 191:2010）所必需的基础信息。报告说明如何按照该中间视觉光度系统计算中间视觉量，包括适应系数 m 的计算方法；规定了这些计算应采用何种适应场，并给出支持这一适应场选择的背景信息。
This report gives essential information necessary for consistent implementation of the CIE system for mesopic photometry (CIE 191:2010) in practical outdoor lighting applications. It describes how to calculate mesopic quantities according to the CIE system for mesopic photometry, including the method for calculating the adaptation coefficient, m. The adaptation field that should be used in these calculations is defined and background information to support this choice of adaptation field is presented.