Colorimeters carry out quantitative and qualitative measurements of colors, including parameters such as saturation, hues and luminosity, as well as perception, quantity and depth, based on the Beer-Lambert law, according to which the absorption of light transmitted through the medium is directly proportional to the concentration of the color light medium to the measuring device. This analyzes the color compared to an existing standard, and then a microprocessor then calculates the absorbance or transmittance percentage, so the computer measures the absorbance or transmittance percentage, both measures of how much light of a particular color is transmitted by an object or solution.
The radiant energy of the light source is influenced on the object or solution, the reflected radiant power passes through one of the three tristimulus filters and falls on the photodetector, generating a response proportional to the corresponding tristimulus value of the object-source combination; subsequently, these raw data are transferred to a microprocessor for the calculation of the absolute tristimulus values. That is, the colorimeters determine the color as a function of the red.