亮度系数 meaning in English

brightness coefficient aqueous
coefficient of luminous intensity (cil)
luminance coefficient
luminance factor

Standard test method for measuring the coefficient of retroreflected luminance of pavement markings in a standard condition of wetness
标准潮湿条件下路面标记反射亮度系数测量的标准试验方法
Standard test method for measuring the coefficient of retroreflected luminance of pavement markings in a standard condition of continuous wetting
连续浸润标准条件下路面标记反射亮度系数测量的标准试验方法