纸和纸板.漫反射法测定颜色.第3部分:室内照明条件（D50/2°）

[中文适用范围]： 本标准规定了消除镜面光泽度的漫反射法测量纸和纸板颜色的方法。 本文件主要用于测量印刷艺术行业使用的纸张和纸板的颜色，该行业规定根据 ISO 13655 在 D50/2° 条件下测量颜色。 该方法与 ISO 13655 的不同之处在于将照明的 UV 内容调整到不同的级别。 该方法可用于测定含有荧光增白剂的纸张或纸板的颜色，只要将测试件上的照明的紫外线含量调整为符合 CIE 光源 C 中的紫外线含量，并使用满足以下要求的荧光参考标准： ISO 2469 规定的国际荧光参考标准 3 级 (IR3) 的要求，以及由授权实验室提供的指定 ISO 亮度值，如 ISO 2470-1 中所述。 本文件不适用于含有荧光染料或颜料的彩色纸或纸板。 [外文原描述]： This document specifies a method for measuring the colour of paper and board by the diffuse reflectance method with the elimination of specular gloss. This document is primarily intended for measuring the colour of paper and board to be used in the graphic arts industry, where that industry specifies the measurement of colour under D50/2° conditions in accordance with ISO 13655. This method differs from ISO 13655, in that the UV content of the illumination is adjusted to a different level. The method can be used to determine the colour of papers or boards that contain fluorescent whitening agents, provided the UV content of the illumination on the test piece has been adjusted to conform to that in the CIE illuminant C, using a fluorescent reference standard that fulfils the requirements for international fluorescent reference standards of level 3 (IR3) as prescribed by ISO 2469 with an assigned ISO brightness value provided by an authorized laboratory, as described in ISO 2470‑1. This document is not applicable to coloured papers or boards that incorporate fluorescent dyes or pigments.