NF T33 - 313-2-2018 Analytical Colorimetry Part 2: Saunderson correction, solutions to the Kubelka-Munk equation, tinctorial strength, hiding power specifies a test method for evaluating the Optical Property of materials through Colorimetry. This standard covers Saunderson correction, analytical methods for the Kubelka-Munk equation, and calculations and analyses of tinctorial strength and hiding power based on this, with an emphasis on evaluating the visual and covering performance of coatings, pigments, and related materials. Through standardized testing procedures and calculation formulas, this standard provides technical guidance for scientific research institutions, production enterprises and quality control personnel to accurately evaluate Optical inspection characteristics, which helps to optimize material formulation, improve product mass and standardize the development of the industry.