Pyxis ST-774 Inline Sensor

Pyxis ST-774

The ST-774 measures the oxygen partial pressure that is at equilibrium with the dissolved oxygen in water governed by Henry’s law (DO/ppb = K PO2)

The Pyxis Lab® ST-774 is an ultra-low range dissolved oxygen (DO) sensor with a lower limit of detection 0.4 ppb (µg/L). Our design is based on the principle of fluorescence quenching to determine the partial pressure of dissolved oxygen in water and incorporates Pyxis’ advanced technology in the field of fluorescence detection. The ST-774 offers the robustness associated with optical DO sensor technology while achieving the ultra-low detection limit compatible to an amperometric DO sensor.


  • 0.0-2,000μg/L measurement range with 0.1 μg/L Limit of Detection (LOD)
  • Built-in temperature and pressure sensors
  • Accurate and stable measurement with ultra-low drift
  • Built-in transmitter without the need of using a preamplifier or meter head
  • Dual outputs: isolated 4-20 mA signal and RS-485 Modbus
  • ST-774 DO Sensor w/Flow Cell
  • Long-distance transmission with higher stability and accuracy
  • Wireless Calibration, Diagnostics, Data Trend via uPyxis APP when used with MA-CR Adapter
  • Zero-point EASY calibration using catalyzed Sulfite ZERO Calibration Kit
  • Optional Zero-point calibration with Nitrogen and slope calibration in O2-containing calibration gas


Typical applications

  • HP Boiler Feedwater / Deaerator Storage
  • Power Facilities
  • Ultra-Pure Water
  • Closed Loops
  • Condensate Return
  • Beverage Production / Post Fermentation
  • Semi-Conductor Rinse Water

Product information



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United Kingdom

01438 759 595

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