iPR FR² Full Range Inline Process Refractometer

The iPR-H2 is a full-range in-line process refractometer. The integrated optics and electronics are designed to provide a very wide measuring range from 1.3200 – 1.5300 RI (0-100 Brix) without major compromises in resolution of 0.01 Brix and accuracy from +/- 0.05 Brix. With its integrated water cooling system, measurements at process temperatures of up to 150°C are easily possible.


The iPR FR² (Full range) is a fully automatic process refractometer that continuously measures the refractive index and thus the concentration of solids in solution or the mixing ratios of binary or quasi-binary liquid mixtures. The measurement is independent of light intensity from the light-emitting diode (LED) and is free of signal drift, granting high precision and better process control. Colour, turbidity, undissolved particles, or gas bubbles do not affect the measurement. You can choose from 2 wide measuring ranges.

The iPR FR² is a stand-alone process sensor with an integrated, illuminated display, which does not require an external electronic unit. Its special design and electronic configuration make it highly flexible and very easy to operate. The programming with Windows software is also very easy. Optional a Data Logger is available.

The stainless steel measuring head is:

  • IP69K protection class-tested by TÜV
  • Chemical resistant
  • Food safe
  • CIP (clean in place) capability

The iPR FR² measuring head can be installed in pipes, reactor vessels, mixing tanks, kettles, boiling pans, and evaporators using different weld-in flanges. The Schmidt + Haensch VariVent Process Adaptor is recommended for pipeline connectivity as it allows for attachment of a cleaning device for units that require cleaning of the sensor face. An optional cleaning nozzle or an ultrasonic cleaning device is also available.

Main specification

Measuring range B1: 1.3320 – 1.5300 / 0 – 100 Brix
Resolution 0.00001 nD
0.01 Brix
Precision ± 0.00007 nD
±0.05 Brix (at 20 °C)


Ambient temperature 0 °C – 45 °C
Process Temperature (max.) + 80 °C without water cooling
+150 °C with water cooling installed
Process Temperature (min.) -10 °C
Process pressure (max.) 1 Mpa (145 psi, 10 bar)

Additional information

Prism YAG
Wetted parts YAG, stainless steel
optional: PTFE
Protection class IP 69 K tested
TÜV Rheinland
Light source/wavelength 589 nm LED
Power supply 24 VDC
Interfaces, switches 2 insulated 4-20 mA analog outputs
2 digital outputs (limited switches, 1 Ampere)
serial output, RS 232 or 422 or USB
Prism cleaning Optional: water, steam or ultrasonic cleaning
Ex-proof version Yes, ATEX Klass Ex II 1G Ex ia II C T4