A refractometer is an optical measuring instrument used to determine the refractive index of a substance. It is used to measure the concentrations of aqueous solutions. It only takes a few drops of liquid.
Mainly used in food, agricultural, chemical and manufacturing industries.
More information on use: https://en.wikipedia.org/wiki/Refractometer
Benchtop or portable digital refractometers for various applications. Designed for the laboratory, they are high precision instruments where the density or specific gravity can be converted into measures such as API,% alcohol, Brix degree and more.