Oxyline® - inline dissolved oxygen measurement with open electrodes

The Oxyline® system is based on an amperometric measurement with open electrodes, which were developed especially for the inline application. We haven chosen a cylinder symmetrical set-up which combines the measuring, the counter and the reference electrode.

The dissolved oxygen is reduced at the measuring electrode. With means of a micro- potentiotat the potential of the measuring electrode is kept at a constant value which is characteristic for the oxygen reduction. The diffusion limited current is proportional to the oxygen concentration within a broad range.

The measurement values are corrected with respect to temperature and flow of the product The calibration is done with an off-line reference measurement. In a bypass system the in situ Faraday calibration can be automatically applied where electrochemically generated oxygen is used.

As shown in the diagram below the oxygen consumption during the growth of yeast can be followed up.
The Oxyline®  system does not show the drawbacks of Clark cells – pressure peaks may destroy the thin membranes or CO2 is diffusing into the electrolyte. OxilineRohr

It does not have thin channels and openings of traditional flow cells, which may cause micro biological trouble. The electrode arrangement of the Oxyline® is fully CIP capable.






  • dissolved oxygen in-line measurement system
  • insensitive against pressure peaks
  • no drift
  • short response time
  • automatic calibration
  • two measurement sites with single instrument
  • robust, easy to operate, simple maintenance and service
  • cost-effective