Colorimetric reagents are used in colimetry tests. A colorimetry test is quick and easy and often cost less than alternative test methods. A colorimeter is an optical measurement that uses color to quantitatively determine the concentration of a compound in a sample. A colorimetric reagent for the compound of interest is added to the sample being tested. A color will develop in proportion to the level of compound present and can be measured by the instrument. Many parameters have EPA approval and meet the regulatory requirements for many industries. Choose from single-parameter colorimeters or multi-parameter colorimeters to meet your application.