Endress+Hauser Oxygen Sensor OXYMAX-W COS61

SKU: COS61 Category:

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


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


Measuring Principle Sensor Oxygen
Application Aeration tank, river monitoring, water treatment, fish farming.
Characteristic Digital, optical (luminescence) dissolved oxygen measurement.
No flow needed – measurement possible in still water.
Measurement range 0mg/l … 20mg/l
0%SAT … 200%SAT
0 … 400hPa
Measuring principle Oxygen-sensitive molecules (marker) are integrated in an optical active layer (fluorescence layer). The fluorescence layer surface is in contact with the medium. The sensor optics are directed at the back of the fluorescence layer. The sensor optics transmit green light pulses to the fluorescence layer. The markers respond (fluoresce) with red light pulses. The duration and intensity of the response signals depend directly on the oxygen contents or partial pressure.
Design – Calibration data saved in sensor.
High degree of EMC protection.
Material Sensor body : stainless steel 1.4571Membrane cap : POM
Dimension Diameter : 40mm
(1.56inch)Length : 220mm
Process temperature -5°C … 60°C
( 23 – 140°F)
Process pressure max. 10bar
temperature sensor NTC temperature sensor, 0 to 50°C
(32 – 122°F)
Connection Process connection: G1″ thread
Cable connection : fixed cable or TOP68 plug-in-head

Endress + Hausers