Chromaticity, as its name implies, is the measurement of color. This measurement is often based on the visual physiology of the human eye, so it will have a certain "subjective" nature, and the measurement results will often "vary from person to person"! The use of instruments to detect chromaticity is an "objective" description of color. This "objective" description can eventually be expressed in numerical form, and the measurement results will be more reliable.
As one of the most basic indicators of sensory traits, liquid color is generally a necessary indicator for quality control. At the same time, based on the different characteristics of various industries, many different industry standard chromaticity systems have been derived, such as Gardner chromaticity in chemical industry, Saybolt chromaticity in petroleum products, Hess-Ives chromaticity in cosmetics industry, platinum-cobalt chromaticity in common liquids, pharmacopoeia in pharmaceutical industry, etc.
That is to say, the chroma value can be obtained by comparing the measured liquid with the standard color by eyes. The limitation of this method is that for very light color samples, visual method can not get accurate measurements, and the conclusions will vary from person to person.
Spectrophotometer takes color as a physical phenomenon which is not dominated by the observer to measure, obtains the tristimulus value of chroma and carries out standard conversion at the same time. It is a flexible and accurate color measurement method.
For high standard and high requirement color measurement
, people will choose spectrophotometer to complete the task of colorimetric measurement, and can measure absolute color and relative color difference.