COLORIMETER

Typical Number in Hospital: 5

Cost Bands: 3,4

References: 9

This is a device used in the clinical chemistry laboratory to identify the concentration of particular components of body fluids (blood, serum, urine, etc.).

There are four main components: a light source, a filter to select a particular wavelength or range of wavelengths, a sample chamber or cuvette, and a photometer. The sample of body fluid is diluted and mixed with a particular reagent to produce a coloured liquid corresponding to the colour selected by the filter. The quantity of light absorbed in the sample in the cuvette is an indication of the quantity of the chemical being tested in the sample. Colorimeters are used in automated chemical analysers to complete some of the tests, or may be separate instruments analysing single samples.