QB/T 1503-2011 Methods for the determination of whiteness of household ceramics ** Specifies the conditions and methods for the determination of whiteness and color difference of household ceramics and ceramic raw materials. The standard covers the measurement of tristimulus values of samples using specific conditions, the method of calculating shade angle, whiteness and chroma. It also includes the requirements for instrument calibrating using standard whiteboards and whiteness meters. The test process requires that the surface of the sample is flat and clean, and the measurement needs to be carried out with appropriate instruments to ensure the accuracy of the results. The final test results should include data such as sample name, shade angle, whiteness, chroma and color difference, and be revised to one decimal place.