EXpure 191

NIR 90°-scattered light sensor

EXpure 191 is a highly accurate compact NIR turbidity sensor for monitoring processes with very low turbidity, e.g. in water applications. It is well suited for swimming pool applications, as well as for some special measuring points in the drinking water sector. The measuring principle used is a 90° scattered light measurement.


Your advantages

  • Compact design with integrated amplifier
  • Nephelometric measurement according to DIN EN 27027 and ISO 7027
  • Durable sapphire windows
  • Easy referencing of the sensor without additional tools
  • LED light source guarantees a durable and stable signal
  • Easy parameterisation via software EXpert
  • No calibration necessary by the user


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Measuring range max.: 0...10 NTU
Resolution: 0,01 NTU
Accuracy: ± 1 % from final value
Reproducibility: ≤ 1 % from final value
Light source: LED
Optical unit: Stainless steel (1.4435)
Windows: Sapphire
Sealing: EPDM
Flow-through cell: Plastic (PE-HD black)
Supply voltage: 24 V DC
Process connection: Thread G1/4"
Process temperature: 1...50 °C
Process pressure: 0...6 bar
Electrical connection: Connector 8-pin (IP68K)
Interfaces: RS485 Modbus, 0/4...20 mA
Parameterisation: Software EXpert
Flow rate: 30...80 l/h
Protection class: IP65



  • Color-independent turbidity measurement
  • Pump performance control
  • Detection of very low turbidities
  • Optimisations when using flocculants
  • Checking the filter performance

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