GB/T 7974-2002 in English

《GB/T 7974-2002纸、纸板和纸浆亮度（白度）的测定 漫射/垂直法》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。
本标准以模拟D65光源、漫射/垂直照明观测条件下，纸、纸板和纸浆对主波长457nm蓝光的漫反射因数（%）表示亮度（白度）测定结果。 对含有荧光增白剂的试样，亦可测定计算出荧光增白效果即荧光亮度（白度）。

Scope

This standard uses the diffuse reflection factor (%) of paper, cardboard and pulp to blue light with a dominant wavelength of 457nm under the simulated D₆₅ light source and diffuse/vertical illumination observation conditions to express the brightness (whiteness) measurement results. For samples containing fluorescent whitening agents, the fluorescent whitening effect, that is, the fluorescent brightness (whiteness), can also be measured and calculated. In this standard method, the basic contents such as the value transfer method, the spectral and geometric characteristics of the instruments used are specified in GB/T 7973 "Measurement method for diffuse reflectance factor of pulp, paper and cardboard (diffuse/perpendicular method)" , so this standard should be read and implemented together with GB/T 7973 "Method for Determination of Diffuse Reflectance Factor of Pulp, Paper and Cardboard (Diffuse/Perpendicular Method)".