A refractometer is a tool that can determine the concentration of a solution by measuring the degree to which light bends as it passes through the solution. Traditionally, this method of measurement was used for honey and vintners, but it is now being used in a wide range of industrial applications.
The first step in calibrating a refractometer is to select the correct calibration liquid. There are many types of solutions available such as calibration oil, AG fluids and sucrose solutions.
Sucrose solutions are particularly useful when calibrating instruments that do not have a temperature control feature as they offer ease of use and are commonly preferred by beverage, sugar and food producers.
Refractive Index Fluoride (RIF) Liquids are another commonly used refractometer fluid and have the same temperature dependency as Brix solutions so they are a good choice when calibrating hand refractometers and Abbe benchtop refractometers that do not have a water bath attached.
Automatic Temperature Compensation Refractometers are also available and are beneficial because they allow the user to maintain accuracy even when the ambient temperature of a room changes by just a few degrees. However, they do require re-calibration about every other month.
To use the refractometer, point the prism end towards a light source and focus the eyepiece until the scale is clearly visible. The refractometer will then interpret the light refraction into refractive index or whatever unit of measure it is programmed to read.
