JWII handheld refractometer

A handheld refractometer is normally used when a measurement of liquid concentration is required. Hand held refractometers have a wide variety of uses from domestic use for home brewers and beverage manufacture, through to industrial process and laboratory applications. Handheld refractometers provide a quick and easy way to measure your liquid concentration or the sweetness of the liquid known as the Brix level. Handheld refractometers come in a variety of types from very basic optical units to fully digital versions.

A refractometer is a device for measuring liquid concentration, it uses light to make this measurement. An LED sends the light into a sapphire or balf prism. The prism is in contact with the liquid and the light from the LED is reflected back from the liquid surface like a mirror. The angle of the reflected light will change depending upon the liquid concentration. This reflected angle is called the angle of refraction. A refractometer uses an optical scale where a shadow is seen with the eye on basic versions, through to more sophisticated refractometers using CCD to capture the returned light from the liquid and electronically calculating the concentration.

The difference between these 2 types of refractometer would be the accuracy and application of the refractometer. A handheld refractometer is typically small and portable and would be a lower accuracy device used for small scale manufacture where a quick measurement is needed but accuracy is not the primary focus. An Abbe refractometer or benchtop refractometer would be used in a fixed position in a central room or laboratory and samples would be brought to the unit for testing. Testing with an Abbe refractometer in a controlled environment would give greater accuracy and repeatability. Abbe or benchtop refractometers come in various formats and accuracies.

Traditional handheld refractometers use the human eye to determine the concentration level. A drop of the liquid is placed on the measurement surface. The device is held up to the light or an illuminator is moved over the measurement surface. You look through the eyepiece and take your reading from the point where the light and dark shadow intersect on the scale.

Refractometers vary dramatically in type and price. They are offered in very basic handheld types, to digital hand held, portable, benchtop, inline process refractometers. These all come with varying accuracies and quality. Prices can vary from a few dollars to thousands of dollars with a typical basic low accuracy handheld refractometer costing $100 to a sophisticated in-line digital refractometer costing upwards of $15,000.00. The type would normally be selected based on the application and accuracy required.

Distilled water can be used to check a refractometer's zero point. Distilled water should be 0 Brix or 1.3330nD on the scale. Another quick way to check a refractometer's reading at a higher level is to use a regular soft drink which is typically 10.5 Brix as a quick check. If greater accuracy is needed water / sugar solutions can be mixed by weight using an accurate weight scale in various concentrations and compared to the refractometer. If accurate calibration is required then you can purchase certified sucrose and refractive index solutions from our company.

The best way to zero a refractometer is to use distilled water. Clean the measurement surface. Place a drop of distilled water on the measurement surface or prism and read. It should show 0 Brix or 1.3330 nD.

If the refractometer is a basic manual version you should measure the interface between light and shadow on the device as the reading. If the device is a digital version it will display the reading typically in Brix (% sugar concentration) or nD (Refractive Index)