Whiteness evaluation: A review and new proposals

Abstract

This publication carries out an in‐depth study of whiteness, various numerical evaluation methods that have been developed over the past 75 years, and review their application and deficiencies in the context of a new proposed Commission Internationale de l'Eclairage (CIE) whiteness formula. The publication first introduces the basic principle of whiteness evaluation from the work of Judd and Selling around 1950, then that of Ganz in the 1970s and finally that of the CIE from 1969 to 1986. The defects of the Judd and Selling formulas became apparent with the use of fluorescent whitening agents. The CIE linear formula cannot predict an optimum for the optical whitening process. Hyperbolic formulas published are much too complicated and are unable to predict correctly the best conditions for that optical whitening. We present a new formula derived from that of the CIE, much simpler than the hyperbolic formulas, and able to predict an optimal shade in the optical whitening process. The formula takes into account the limitations of the white domain; when the blue saturation becomes too great, or when a tint deviation toward green or toward red is too noticeable. The formula gives results identical to those of the CIE formula when the materials are far from commercial whiteness limits. In addition, the formula can be very easily adapted to the CIELAB system and so, gives promising results.

Advances in Non-Electrochemical Sensing of Human Sweat Biomarkers: From Sweat Sampling to Signal Reading

“…The line is extended from the light source towards the chromaticity point of the sample, and where it intersects with the spectral locus is the wavelength of the dominant wavelength of the color sample [147][148][149]. In colorimetric analysis, the change in the color of the color reagent often accompanies a significant change in hue, and the most relevant parameter for color tone is the main wavelength (or complementary wavelength) [150,151]. Analyzing the main wavelength (or complementary wavelength) in the color information of the color reagent can be used to analyze the concentration of the target substance.…”