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Dissolved oxygen sensor
Oxymax COS61

Optical oxygen sensor for water, wastewater and utilities

  • ©Endress+Hauser
  • ©Endress+Hauser

Oxymax COS61 is a high-performance oxygen sensor that offers fast, accurate and drift-free measurement. It supports your process with low maintenance, high availability and easy handling. The sensor's long-term stable fluorescence layer is exclusively oxygen-selective (interference-free), ensuring consistently reliable measurement.


  • Minimum maintenance, maximum availability

  • Fast, drift-free measurement for aeration control and process monitoring

  • Long-term stability for increased process safety

  • High-performing in all aeration processes (SBR, Anamox, etc.)

  • Chemical-free: no electrolyte handling

  • Easy measuring point changeover to optical technology compatible with COS31 and COS41

Field of application

Oxymax COS61 measures the dissolved oxygen concentration in:

  • Wastewater treatment plants:
    - O2 control in the aeration basin
    - Process water treatment and monitoring

  • Water works:
    - Status monitoring of drinking water (oxygen enrichment, corrosion protection, etc.)
    - Water quality monitoring in rivers, lakes or seas

  • Utilities of all industries:
    - O2 control in the biological treatment
    - Process water treatment and monitoring

  • Fish farming:
    - O2 control for optimum growth conditions

Features and specifications

Documents / Manuals / Software

Accessories / Spare parts

Predecessor / Successor

Predecessor: Oxymax W COS31

Success stories


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Fax: +41 61 715 2888
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