Instruments designed to measure a sample's refractive index or polarization of light.
Typical uses for refractometers:
- Laboratory medicine: Used to measure total proteins in blood samples and specific gravity in urine samples
- Gemology: Used to identify gems
- Aquariums: Measure water salinity and specific gravity
- Industry: Measure coolant concentrations
- Homebrewing: Measure fermentable sugars that will be converted to alcohol