Refractometers for Food and Beverage Processing

Refractometers commonly used to detect sugar levels and properties of jams juices, beverages, dairy products and much more.

Electron Machine Corporation developed the first in-line process refractometer more than 50 years ago when orange juice was first concentrated. Since that time, their refractometers have been successfully applied on many more applications including the production of sucrose, fructose, dextrose, soft drinks, fruit juices, dairy, apple sauce, jams, jellies, beer, wine, coffee, tea, vegetable oils, tomato paste, ice cream and honey.

With an extremely durable Sapphire prism as its foundation, the Electron Machine MPR E-Scan combines accurate measurements with ruggedized components in the sensing head combining for years of of dependable and accurate service in harsh food production environments.

Inline Refractometer Adapters, Cleaning Systems & Isolation Valves

There are many different mounting adapters available for the MPR E-Scan refractometer. These adapters have been designed and modified with decades of field experience to provide the most successful installation for specific applications. The video below provides a quick visual tour of the most popular.

For more information visit or call 352-669-3101.

Understanding the Use of Inline Refractometers in Food and Beverage Production

refractometers for jams and jelly production
Inline refractometers are used
for jam and jelly production to
ensure consistency and quality.
This post is intended to give a basic understanding of the use of inline refractometers in commercial food and beverage production


According to Wikipedia, "Refraction is the change in direction of wave propagation due to a change in its transmission medium."

To understand more clearly, consider this. If you place a pencil in a jar of standing in water and look through the jar, it appears to be broken at the water line. When you add sugar to the water, the pencil appears to bend even more. The reason for this is because light travels slower in water than through air. When you dissolve materials (sugar) in the solution, the light will travel even slower.  Understanding this basic concept allows you to understand how you can measure, and therefore control, the concentration on a material in a solution through the use of refraction.

Refractive Index

The refractive index (RI), is the ratio between the speed of light in vacuum and the speed of light in a given media. It determines how much light is bent, or refracted, when entering a material. The Refractive Index of air is 1.0003, and the RI of most gases, liquids, and solids is between 1 and 2.

Refractive Index is defined as:
  • RI= Speed of Light in Vacuum / Speed of Light in a Particular Medium
Applying Refraction to Food and Beverage Processing

Food and beverage industries prefer to use their own units rather than the index of refraction for controlling quality of their product. Examples are measuring sugar content in tomato products, citrus juices, and jams and jellies. These industries prefer to use the % Brix scale, which refers to the sugar concentration. Refractive Index is easily converted to % Brix units through simple calculations.

Inline Refractometers for Large Scale Food and Beverage Production

Industrial inline refractometers directly measure the Refractive Index of process fluids and then display the reading in any number of customer-desired units such as Brix, Percent Solids, Dissolved Solids, etc. 

refractometer in food and beverage process
Inline refractometer in food and beverage process
highlighting sensing element and electronics console.
There are two primary components to an inline refractometer, the electronics console and the sensing head.  

The electronics console usually contains a display of some type, and provides a standard output such as 4-20mA. Optionally, there may be some form of networking protocol such as HART® or RS-232/422. 

The sensing head is installed in line by mounting the prism assembly in a pipe and inserting this pipe section in the process line. Vessel mounting is accommodated by having the prism assembly inserted in a flange that can be attached to a storage tank or mixing tank. 

For more information on any commercial or industrial application for inline refractometers, contact visit Electron Machine at or call 352-669-3101.

Industrial Refractive Index Transmitters

Loop diagram
Example flow loop diagram
showing role of transmitter.
Transmitters are process control field devices. They receive input from a connected process sensor, then convert the sensor signal to an output signal using a transmission protocol. The output signal is passed to a monitoring, control, or decision device for use in documenting, regulating, or monitoring a process or operation.

Transmitters are available for almost every measured parameter in process control, and often referred to according to the process condition which they measure.

The refractive index determines how much light is bent, or refracted, when entering a material. When light moves from one medium to another, it changes direction (refracted). This change in the direction of the light can be measured and applied to properties of the material.

Refractive Index transmitter
Example of Industrial Refractive Indextransmitter/controller.
Can act as transmitter alone, or with
optional PID control functions.
Industrial Refractive Index transmitters directly measure the refractive index of process fluids. It then conditions the input signal, making it linear, and then converts that signal into any number of customer-desired units (Brix, Percent Solids, Dissolved Solids, SGU, R.I., etc.) and transmits a standard, linear electrical output (4 to 20 mA) that can be utilized by receiving instruments and displays.

Many transmitters are provided with higher order functions in addition to merely converting an input signal to an output signal. On board displays, keypads, Bluetooth connectivity, and a host of industry standard communication protocols can also be had as an integral part of many process transmitters. Other functions that provide alarm or safety action are more frequently part of the transmitter package, as well.

Industrial Refractive Index transmitters have evolved from simple signal conversion devices to higher functioning, efficient, easy to apply and maintain instruments utilized for providing input to process control systems.

For more information on Industrial Refractive Index transmitters visit Electron Machine at or call 352-669-3101.