Colorimeter- Definition, Principle, Parts, Uses, Examples


A colorimeter is an instrument or device that measures the color or concentration of a solution by comparing it with a standard color or a pure solvent. It uses a photocell to detect the amount of light that passes through the solution and applies the Beer–Lambert law, which relates the concentration and the absorbance of light. A colorimeter can have three filters that simulate human vision.

A colorimeter can be used for various purposes, such as:

  • Analyzing the quality of printing ink and paper
  • Determining the biochemical composition of biological samples
  • Measuring the purity and chemical content of water
  • Evaluating the color contrast and brightness of screens
  • Testing the UV protection level of skin-care products
  • Identifying the color and quality of gemstones
  • Estimating the amount of hemoglobin in the blood

A colorimeter is different from a spectrophotometer, which measures the intensity of light at different wavelengths across the electromagnetic spectrum. A colorimeter only measures light in the visible range (400 nm to 700 nm) and uses a single wavelength or a narrow band of wavelengths for each measurement. A spectrophotometer can provide more detailed information about the spectral properties of a solution, but a colorimeter is simpler, cheaper, and faster to use.