Refractometer
From Wikipedia, the free encyclopedia
A refractometer is an optical instrument that is used to determine the refractive index of a substance or some physical property of a substance that is directly related to its refractive index. Certain types of refractometers can be used for measuring gases, liquids, and even transparent or translucent solids such as gemstones.
A refractometer can be used to determine the identity of an unknown substance based on its refractive index, to assess the purity of a particular substance, or to determine the concentration of one substance dissolved in another. Most commonly, refractometers are used for measuring fluid concentrations such as the sugar content (Brix level) of fruits, vegetables, juices and carbonated beverages, or of cutting fluids, urine specific gravity, blood protein concentration, salinity, antifreeze, industrial fluids, etc.
[edit] Types of refractometers
There are four main types of fluid refractometers: traditional handheld refractometers, digital handheld refractometers, Abbe refractometers, and inline process refractometers.
There is also the Rayleigh Refractometer used (typically) for measuring the refractive indices of gases.

