Analysis of the Reasons for Different Measurement Values of Yellow Index YI

The yellow index, polymer chromaticity, whiteness, brightness, b-value and other indicators are widely used in the chemical industry. The calculation formula for YI is very simple, and can be accurately calculated through the three stimulus values XYZ. As long as a colorimeter can measure XYZ, the yellow index YI value can be obtained, but these YI values are too far apart. What factors affect the results of YI that comply with GB/T39822, HG/T3862, ASTM D6290, as well as the consistency of data between upstream and downstream customers?