Sper Scientific sells four main refractometer types: Optical Refractometers, Digital Handheld Refractometers, Waterproof Refractometers and Desktop or Laboratory Refractometers. Industries that use our refractometers include: Pharmaceutical, Chemical, Petroleum, Petro-Chemical, and Food & Beverage industries. Our refractometers measure items such as: honey, Brix or sugar content of a liquid, salinity or salt content of a liquid, battery coolant, and urine.