• Measuring ranges:
    • 0.01 to 100 mg/l
    • 0.00 to 1000% SAT
    • 0 to 2000 hPa
  • 20 to 120°F (–5 to 50°C) process temperature
  • Max 145 psi (10 bar) process pressure
  • 0.01 mg/l (0.01 ppm) measured value resolution
  • ±1% of measured value accuracy
  • ±1% of measured value repeatability
  • Approx 300 nA signal current in air
  • IP68 protection


The E+H Oxymax COS51D oxygen sensor is a reliable and highly accurate oxygen sensor for a wide variety of water and wastewater applications, including use in hazardous areas. The COS51D is designed for low maintenance and a long operating life. The sensor offers digital data transmission, including internal storage of calibration data and no electromagnetic interference during communication to the transmitter. The sensor's potentiostatic, amperometric, three-electrode system ensures long-term, stable measurement; long maintenance intervals and intelligent self-monitoring. The sensor also features a membrane covering, allowing high O2 selectivity and minimum maintenance and calibration effort.

The COS51D features Memosens technology, offering greater process and data safety, easy handling, and predictive maintenance. The non-contact inductive signal transmission eliminates problems associated with moisture, such as corrosion and distortion. The intrinsically safe electronics allow application in hazardous areas. Since measured values are transmitted digitally, data is free from interference and errors are immediately detected. Sensors with Memosens technology also have integrated electronics that store calibration data and operating information, allowing for calibration separately from the measuring point and protected from the effects of weather. Maintenance intervals can be defined based on all stored sensor load and calibration data.

E+H Oxymax COS51D Oxygen Sensor Applications

  • Wastewater treatment plants
    • O2 control in the aeration basin
    • Process water treatment and monitoring
  • Water works
    • Status monitoring of drinking water
    • Water quality monitoring in rivers, lakes or seas
  • Utility monitoring of all industries
    • O2 control in the biological treatment
    • Process water treatment and monitoring