In modern process industries, accurate concentration measurement is essential for product quality, process efficiency, and reliable automation. Whether the application involves sugar/Brix measurement, acids, alkaline solutions, solvents, hydrocarbons, or other liquid processes, the measurement device must provide stable and repeatable data directly from the process line.
The Vaisala Polaris PR53GP Probe Process Refractometer is designed for reliable inline concentration measurement in demanding industrial environments. Based on optical refractive index measurement, it provides continuous, fast, and accurate concentration data without being affected by bubbles, particles, suspended solids, crystals, or liquid color.
What Is the PR53GP?
The PR53GP is a general-purpose probe process refractometer developed for measuring concentrations in different liquid applications. It can be installed directly into a pipeline or tank and is suitable for both production and quality-control applications.
Typical industries include sugar, chemical, petrochemical, and other process industries where accurate liquid concentration measurement is required. The instrument can measure sugar/Brix, sulfuric acid, sodium hydroxide, and more than 500 available concentration curves.
Optical Measurement Based on Refractive Index
The PR53GP measures concentration using refractive index, also known as RI. Refractive index is a reliable optical property of liquids and responds to dissolved material in the process medium.
Because the measurement is optical, it is not affected by bubbles, particles, crystals, suspended solids, or the color of the liquid. This makes the PR53GP suitable for applications where traditional measurement methods may struggle due to process impurities or changing visual appearance.
Accurate and Stable Measurement
One of the main advantages of the PR53GP is its drift-free optical measurement principle. The refractive index measurement provides accurate and stable data over long-term operation.
The instrument also includes integrated temperature measurement. This allows the system to compensate for changing process temperature, so concentration measurement remains reliable even when process temperature varies.
According to the datasheet, the refractive index measurement range is 1.32 to 1.54 nD, corresponding to 0 to 100 °Bx. Accuracy is specified as ±0.00014 nD, equivalent to 0.1 °Bx, with a repeatability of ±0.00002 nD.
Designed for Inline Process Installation
The PR53GP can be installed in standard flanges, making it easy to mount into process lines. Clamp and flange connection options are available, allowing the device to adapt to different process requirements.
The instrument can also be installed with an optional flange-mounted pipe flow cell accessory, enabling use in a wide variety of pipe sizes. For demanding high-temperature or high-pressure processes, an optional cooling cover accessory is available.
Reliable Performance in Demanding Conditions
The PR53GP is designed for industrial operating environments. The process temperature range is -40 °C to +150 °C, and the design pressure is 40 bar. The housing has IP66 and IP67 protection ratings, as well as Type 4X classification.
Wetted parts are made from EN 1.4404 / AISI 316L stainless steel, while the prism is made from sapphire monocrystalline material. These materials support durability and reliable operation in challenging process conditions.
Self-Cleaning and Optional Wash System
In many applications, the PR53GP does not require a wash system because the shear force of the process flow helps keep the measurement point clean. This self-cleaning effect supports stable long-term operation with reduced maintenance needs.
For sticky or more demanding process conditions, a powerful wash system can be used to ensure correct measurement. The Indigo520 transmitter is required when washing is needed for the application or installation position.
Outputs and Integration
The PR53GP includes built-in 4–20 mA and Modbus RTU outputs. Output parameters include refractive index, temperature, concentration, and quality factor.
The device operates with a nominal 24 VDC supply, with an operating voltage range of 9 to 30 VDC. Power consumption is less than 1 W, supporting efficient integration into process instrumentation systems.
Compatibility with Vaisala Indigo520
The PR53GP can be connected directly or interfaced with the Vaisala Indigo520 transmitter. When used with Indigo520, the system provides access to features such as data storage, graphical interface, and analog and digital interfaces.
Settings, measurement parameters, and service updates can be adjusted through the Indigo520 transmitter or by using Vaisala software via USB connection.
Typical Applications
The PR53GP is suitable for crystallizers, wet scrubbers, reactors, transport pipelines, blending systems, and distillation operations. It is also well suited for sugar production, chemical processing, petrochemical applications, and general liquid concentration monitoring.
In sugar applications, the device can be used for Brix and concentration measurement. In chemical processes, it supports concentration control for acids, alkaline solutions, solvents, and many other liquids.
Why Choose PR53GP?
The PR53GP is a strong choice for facilities that require continuous, accurate, and maintenance-friendly concentration measurement. Its optical measurement principle provides stable results without being affected by common process disturbances such as bubbles, particles, suspended solids, crystals, or color.
Its stainless steel construction, sapphire prism, flange and clamp mounting options, built-in outputs, and Indigo520 compatibility make it suitable for both new process installations and modernization projects.
Conclusion
The Vaisala Polaris PR53GP Probe Process Refractometer provides accurate inline concentration measurement for a wide range of industrial liquid processes. With refractive index technology, integrated temperature measurement, robust stainless steel construction, built-in 4–20 mA and Modbus RTU outputs, and compatibility with the Indigo520 transmitter, it offers a reliable solution for production and quality-control applications.
For sugar, chemical, petrochemical, and general process industries, the PR53GP delivers stable, continuous, and accurate concentration data directly from the process stream.