Refractometer

If you're in need of a refractometer, you've come to the right place. To help you determine which refractometer model will best meet your needs, ask yourself the following questions before purchasing.

Do you need a portable or stationary refractometer?
Your answer to this question depends largely on the nature of the refractomer's intended use. Will you be measuring the refractive index in a laboratory or on a manufacturing production line where you will remain in the same place taking repetitive measurements with your refractometer? Or will you be measuring the refractive index on the go, in the field or in many different scenarios and locations?

An Abbe refractometer typically is a tabletop or benchtop device for stationary use. Analog or digital handheld refractometers usually are lightweight and portable, with some even capable of being stored in your pocket. These pocket-size refractometers especially are handy for taking on-the-spot measurements in breweries, vineyards and even automotive body shops.

What measurement accuracy is required?
An analog handheld refractometer with an optical reading scale should have an accuracy of ± 0.5% Brix. A modern digital handheld refractometer should have an accuracy of ± 0.2% Brix. The accuracy of an ABBE refractometer should be ± 0.3% Brix.

Because refractive index is temperature dependent, to ensure the most accurate measurement readings using any refractometer, it is important to allow the sample, refractometer and ambient temperatures to equalize before measuring. This step is essential, even when using a refractometer with automatic temperature compensation. To know whether the temperatures have come to an equilibrium, take five measurements in a row. The readings should not vary by more than the stated accuracy or precision of the refractometer.

Is a calibration certificate needed for your refractometer?
All refractometers from PCE Instruments (PCE) are manufacturer or factory calibrated. PCE's handheld and Abbe refractometer models also can be zeroed or calibrated at any time by the user.

For companies requiring an ISO calibration certificate, many PCE refractometer products can be calibrated in an ISO-certified laboratory environment against certain reference standards (certified test fluids). Refractometer models with an ISO calibration option will feature an ISO calibration certificate as an accessory available for an additional fee.

In the following, you can see some example indicator scales of some refractometers. If the measurement parameters you require are not available with the products we offer, please do as described below or get in touch with our engineers and technicians who are happy to give advice on our refractometers

For example, if the result is 12.9 % Brix, you can do a dry test of the same substance in a drying cabinet or a chemical analysis of it in a laboratory. In this example, the result is 8.2 % solids content.

You now have to divide the two results (12.9 : 8.2). Result = 1.57. Now you know the correlation between the refractometer and the laboratory result. If you now use the refractometer for in-process or field measurements, you only need to divide the measured value by 1.57 to get the actual laboratory value.

Follow the links to find some more information about our refractometers (Conversion charts )  as well as detailed instructionsto compare refractive values measured by different refractometers. Lots of our refractometers display the reading in degrees Brix. A liquid has one degree Brix (=1 % Brix) if it has the same density as a solution of 1 g of sucrose in 99 g of water. It has 10 Brix (=10 % Brix) if it has the same density as a solution of 10 g of sucrose in 90 g of water. The sucrose serves as the reference for the sugar content. The amount of soluble dry solids in a liquid (and thus approximately the sugar content) is usually displayed in "degrees Brix" (° Brix). This indirectly provides an objective value of the ripeness of a fruit. Some EC marketing standards (e. g. for kiwi fruits and melons) now stipulate that a „sufficiently ripe“ fruit must fulfil certain Brix values. This unit of measurement which is very common in the use of refractometers is named after Adolf F. Brix, a scientist of the 19th century who developed this calibration in 1870 in order to determine the sugar content of liquids. The EC marketing standards for kiwi fruit and melons / watermelons expressly stipulate that the Brix value must be measured with a refractometer in order to determine the harvest maturity of fruit. The Abbe refractometer is a special type of refractometer. This type of refractometer is an optical device that determines the refractive index of liquids. It is a total refractometer, which means that its measuring principle is based on the fact that the critical angle of the total reflection at an interface depends on the refractive indices of the involved optical media. The total reflection takes place at the interface between the glass prism with a known, high refractive index and the liquid to be measured which is optically thinner and has a lower refractive index. The interior design of the Abbe refractometer enables precise determination of the critical angle with a thin liquid layer which is applied between two glass prisms. These refractometers are available in our online shop.

Should you require additional assistance in determining the right refractometer product for your application, please don't hesistate to contact us at or +44 (0) 2380 987 035 for PCE Instruments UK, or or +1 (561) 320-9162 for PCE Americas Inc.