This dissolved oxygen (DO) sensor employs the ‘dynamic luminescence quenching’ principle. It provides an extremely stable, accurate, low-maintenance DO measuring system. Sensor optics include a lens, blue LED and filter, red LED and filter, and a photodetector or photodiodeWhen the blue LED emits light, it causes the lumiphore molecules embedded in the gas-permeable sensing foil to emit red photons.

The RDO Pro sensor measures the ‘phase’ (or delay) of the returned signal compared to the excitation signal, which makes it based on the ‘lifetime’ rather than the ‘intensity’ of the luminescence. The presence of oxygen in the foil quenches the luminescence and causes a phase shift in returned signal detected by the photodiode. The phase difference between the blue excitation light and the return red light is measured, and the result is used to quantify the dissolved oxygen present.

The sensor may be interfaced direct to a site PLC or into one of the available display/controllers.


  • Luminescence phase shift principle
  • Optional Air clean system
  • Versatile mounting options
  • 0-20ppm range
  • Rugged Waterproof construction
  • Corrosion resistant materials
  • Connects direct to PLC or to AV38 interface/display or Aquapro multi input controller
  • Internal sensor diagnostics

  • High precision & accuracy with fast & stable response
  • No conditioning necessary prior to use— fast start up
  • Retains calibration in head

  • Municipal/industrial wastewater
  • Final effluent monitoring
  • Process monitoring
  • River monitoring stations
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