The colorimeter is a device that allows color measurement.
Colorimeter is a term that is formed with the noun color (the sensation that light rays produce when they impress the organs of vision) and the suffix ‒́meter (which refers to a measurement or a device used to measure).
A measuring instrument that is used in the field of colorimetry is called a colorimeter . The notion of colorimetry, meanwhile, refers to chemical analysis based on the measurement of the intensity of a color.
What is a colorimeter
Colorimeters are tools that make it possible to identify a color and a shade . What they do is develop a precise and objective measurement.
To fulfill their function, colorimeters usually analyze three variables, known as tristimulus values or coordinates . They have filters (blue, green and red) that are responsible for simulating the sensitivity that people's eyes have to light rays.
The importance of absorbance
The operation of the colorimeter is based on absorbance . This concept refers to how radiation is attenuated when passing through a substance .
Absorbance is expressed as a logarithm that reflects the link between outgoing intensity and incoming intensity. It is important to mention that absorbance is proportional to the concentration of a substance.
The colorimeter, in this framework, is responsible for measuring the absorbance of a solution at a specific light frequency. For this, it has sensors that record how much light passed through the solution and compares the amount entering with the amount absorbed.
Colorimeter measurements offer numerical values . This leaves aside the errors that can occur when working with the perception of the human eye.
Colorimeters are based on absorbance.
Uses of the colorimeter
The most common use of the colorimeter is to make measurements of a certain color and establish comparisons with other samples . From this work, multiple possibilities open up.
When you need to generate products that are identical, colorimeters are vital so that there are no chromatic differences. These equipment also allow the production of parts that replace or combine with others that are the same.
The standardization of dye formulas and the color control of plastics, printed materials, ceramics, tiles and other products are also functions that colorimeters fulfill.
Another use of the colorimeter is associated with the evaluation of water treatments. Many times these devices make it possible to know if the treated water complies with current standards.
Differences with the spectrophotometer
As we expressed above, colorimeters analyze tristimulus coordinates. At this point it is interesting to note the existence of more accurate measuring devices, called spectrophotometers .
The spectrophotometer is used in spectrophotometry , which is the procedure carried out to measure the level of light absorbed by a substance with respect to a certain wavelength. In other words, the spectrophotometer measures color across the entire spectrum, calculating the total reflectance of each visible wavelength .
It can be said that the spectrophotometer is more versatile and precise than the colorimeter. Therefore, if complex or in-depth color analysis is required, the spectrophotometer is usually favored over the colorimeter.