GB/T 21245-2007 in English

《GB/T 21245-2007纸和纸板颜色的测定（C/2°漫反射法）》由TC141（全国造纸工业标准化技术委员会）归口，主管部门为中国轻工业联合会。
本标准首次发布。本标准等同采用ISO5631:2000,仅作少量编辑性修改,在技术内容上完全相同。
本标准规定了用消除光泽的漫反射法测定纸和纸板颜色的方法。
本标准不适用于加入荧光染料或颜料染色的纸和纸板。当仪器光源照射在试样上的紫外辐射量调准至与ISO2470规定的授权实验室提供的在CIE 照明体C 条件下的荧光参比标准一致时,本标准可用于测定含有荧光增白剂的纸和纸板。

Scope

This standard specifies a method for the determination of the color of paper and board by the diffuse reflectance method with degloss. This standard does not apply to paper and paperboard dyed with fluorescent dyes or pigments. When the amount of ultraviolet radiation irradiated on the sample by the light source of the instrument is adjusted to be consistent with the fluorescence reference standard provided by the authorized laboratory specified in ISO 2470 under the condition of CIE illuminant C, this standard can be used to determine the concentration of fluorescent whitening agent. of paper and cardboard.