Refractometer for Juice Concentrate

fruit juice concentration line
Fruit juice concentration line
Reprinted with permission from K-Patents

Fruit juice concentration requires the partial removal of water content so that all the solid components such as fruit sugars, minerals and vitamins are left in a more concentrated solution. The purpose of concentration is to ensure longer storage life and easier transportation.
Chemical curve: R.I. per BRIX at Ref. Temp. of 20˚C
Chemical curve


Typical end products: Fruit and vegetable juice concentrate (apple, orange, grapefruit, pineapple, tomato, passion fruit, mango, carrot, grape, cherry, cranberry, guava, pomegranate etc.)

After juice extraction, screening and centrifugal purification, the juice goes to a primary tank. At this stage, the juice concentration is inconsistent, varying from 9 to 12 Brix. The concentration depends on various factors such as fruit quality and annual rainfall. The juice is then fed to the evaporation plant.

For fruit juice concentration, a three-stage falling film evaporation plant is commonly used. The evaporators have a constant boiling rate. In the evaporation process, the concentration value is typically increased from 10 to 65 Brix.


The K-Patents Sanitary Refractometer PR-23-AC is mounted on the evaporator outlet. It provides a signal to a controller regulating the Brix value by varying the evaporator inlet flow.

If the Brix value increases, the valve allows a product flow rate increase through evaporators. This brings the Brix value back to the set-point. Typical measurement range is 30-80 Brix.


K-Patents Sanitary Compact Refractometer PR-23-AC for small pipe line sizes of 2.5 inch and smaller.  
K-Patents Sanitary Compact Refractometer PR-23-AC
K-Patents Sanitary
Compact Refractometer
  • The PR-23-AC sensor is installed in the pipe bend. It is angle mounted on the outer corner of the pipe bend directly, or by a flow cell using a 3A Sanitary clamp or Varivent® connection.
  • Measurement range: Refractive Index (nD) 1.3200 – 1.5300, corresponding to 0-100 Brix. 

Process Control: Switch, Transmitter, or Hybrid? What to Choose.

switch, transmitter, or hybrid
Switch, transmitter, or hybrid?
What to choose.
For decades, process instrumentation specifiers have faced the decision whether to use a mechanical switch or a continuous transmitter for a given application. Either type of instrument can be used to effectively control industrial processes and protect equipment and personnel -- and each has associated pros and cons. Application specifics typically drive decision-making, dictating which approach is most effective from performance, cost and lifecycle support perspectives.

The white paper below, courtesy of SOR, Inc., provides a guideline for choosing between switches, transmitters, or hybrids.

Carbon Dioxide Monitoring in Breweries

Hazardous Gas Detection in Brewing
Hazardous Gas Detection in Brewing
The brewing industry worldwide produces close to $300 billion in revenue, comprising multinational companies as well as many micro- breweries. Brewing processes generate carbon dioxide and can create environments that may be hazardous to operators working throughout these facilities.


Carbon dioxide is present in fermentation and carbonation processes as well as within other brewing facility processing and bottling areas. Carbon dioxide is considered to be a heavier-than-air gas, with current TWA of only 5,000 ppm. Current IDLH (Immediately Dangerous to Life and Health) is 40,000 ppm, or 4% by volume.


Infrared gas monitors from MSA permanent instruments recently enabled a global brewer to achieve the best solution for their application. MSA provided a sample draw system using a standard MSA Ultima® XIR Infrared Sensor with range of 0-5% by volume. System design had to meet this facility's instrumentation standard as well as provide necessary outputs and contacts to properly integrate with each facility’s existing communications network. Audible and visual alarms are part of the NEMA 4X system required to function within these very wet areas; a special end-of-line lter was also developed. These systems must operate 24/7 with very low maintenance requirements, resulting in overall low cost of ownership.


MSA, working with the brewer, jointly developed the product and program that was introduced to all key instrumentation and electrical technicians as they upgraded each facility. MSA provided not only site start-up, but also site-specific operator training to transition to this new design as transparently as possible. With a nationwide network of eld service personnel, MSA supports these systems in a timely manner, at reasonably low customer cost.

For more information about hazardous gas detection, contact:
Instrument Specialties Inc.
3885 St. Johns Parkway
Sanford, FL 32771
phone 407.324.7800
fax 407.324.1104