iPR HR² Inline Process High-Resolution Refractometer

The iPr-HR2 is perfect for all applications where measurements need to be as precise as laboratory testing with its extremely precise process sensor delivering the highest resolution: up to 5 x 10-6 RI (2 x 103 Brix), precision up to +/- 4 x 10-6 RI (+/- 2 x 10-2 Brix). With a special water cooling system, the iPR-HR2 allows measuring in hot process environments and cleaning in place (CIP).

This device helps you to monitor and control your production process. Similar to a laboratory refractometer the iPR-HR2 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. Connecting and programming the device using Windows software is also very simple. An optional data logger is available.

The iPR HR² (High Resolution) is a fully automated high-resolution process refractometer that continuously measures the refractive index and thus, the concentration of a binary or quasi-binary liquid mixture.
The iPR HR² is specifically developed for the control of liquids with a very low solid content (e.g. light drinks) as their RI determination requires high resolution and precision.
The stainless steel measuring head is:

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

The iPR HR² 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 the 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.


  • Pharmaceuticals
  • Nutraceuticals
  • Diet beverages
  • Salinity
  • Low concentration residues in condensates

Main specification

Measuring range 1.3320 – 1.3720 / 0 – 25 Brix 
Resolution 0.000005 nD / 0.002 Brix
B2: 0.00002 nD / 0.02 Brix
Precision ±0,00004 nD
±0,02 Brix
(±0,01 – 2% Brix at 20 °C)


Ambient temperature 0 °C – 45 °C
Process Temperature (max.) + 80 °C without watercooling
+100 °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 insulated 4 – 20 mA analog outputs
2 serial outputs RS232 or RS 422 and USB
Prism cleaning Optional: water, steam or ultra sonic cleaning
Ex-proof version No