Colorimeters and Their Functions
A colorimeter, utilized in Colorimetry, functions as a light-sensitive device employed to measure the absorbance and transmittance of light passing through a liquid sample. The Hunter, a filter colorimeter, discerns reflected color components by utilizing a three-dimensional color scale.
Typically used to quantify the concentration of a known solute in a given solution, the colorimeter follows the Beer-Lambert law, asserting a direct proportionality between absorption and the concentration of the liquid sample. When assessing color against a predefined standard, the colorimeter directs light through a liquid sample.
Louis J Duboscq is acknowledged for inventing the colorimeter in 1870, and in the 1940s, Richard Hunter introduced the Lab tri-stimulus model. This model, crafted to achieve nearly uniform spacing of perceived color differences, underwent various iterations of the Hunter L, a, b color scale before the final formulas were established in 1966.
The L, a, b color scale emulates the human eye's perception of color:
- L scale: Represents lightness or darkness, where a low number (0-50) indicates darkness and a high number (51-100) indicates light.
- a scale: Reflects redness or greenness, with a positive number indicating red and a negative number indicating green.
- b scale: Indicates yellowness or blueness, with a positive number denoting yellow and a negative number denoting blue.
Color photometers: Assess color transmission and reflection.
Colorimeters are frequently employed to compare new samples with existing ones. Applications include monitoring the growth of yeast or bacterial cultures, evaluating beverage color, and measuring ink colors.
Colorimeters and Their Functions
