CIE Whiteness and Tint: Possible Improvements

To introduce some measure of standardization in the face of the endless variety of whiteness formulas being used, the "Commission internationale de l'éclairage" proposed in 1986 a whiteness and a tint formula for practical trials. The formulas in question were simplified derivatives of those used in the Ganz/Griesser method. The difference is that the CIE proposes fixed formula parameters and recommends the formulas only for relative assessments valid just for measurements with a single instrument at a given time and without reference to a white scale. Use of the two formulas is restricted to samples differing not too widely in tint and fluorescence. With these restrictions the formulas yield relative, not absolute, white assessments reportedly adequate for commercial use in many cases. The measuring instruments must have sample illumination resembling daylight.