Refractometers are one of the most commonly used optical instruments in food preparation, chemical production, and in forensic labs. Refractometry is the process of measuring the extent to which light is "bent" (or refracted) when passing through a transparent solution or solid like a prism. The measurement is converted to a unitless value, which helps to determine a solution's purity, its concentration, and/or its composition.

In Forensic Laboratories, Abbe refractometers are commonly used to identify unknown liquids in clan labs and other drug manufacturing sites. They are also frequently used to determine the concentration of precursor chemicals during inspections to validate amounts used in charging for court cases as well as checking for illicit use. Abbe refractometers are particularly sought out for their high degree of accuracy.

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