Refractometer

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Photo of a Handheld Refractometer used to measure sugar content (Brix level) of fruits. The image includes a view through the eyepiece of the instrument, a small drop of orange juice was put over the measuring prism to take the picture.

A refractometer is an optical instrument that is used to determine the refractive index of a substance. This often refers to 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 such as oils or water-based, 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, for example in carbonated beverages, fruits, juices, honey and or vegetables, etc), blood protein concentration, salinity and specific gravity of urine. Refractometers are also used for measuring fluid concentrations for commercial liquids such as antifreeze, cutting fluid, and industrial fluids.

[edit] Types of refractometers

There are four main types of refractometers: traditional handheld refractometers, digital handheld refractometers, laboratory or Abbe refractometers, and inline process refractometers.

There is also the Rayleigh Refractometer used (typically) for measuring the refractive indices of gases.

In veterinary medicine, a refractometer is used to measure the total plasma protein in a blood sample.

[edit] External links

• Refractometer - Gemstone Buzz uses, procedure & limitations.
• Rayleigh Refractometer: Operational Principles