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OMS 420 – Insitu Oxygen / Combustibles Monitor

In-Situ Oxygen and Combustibles (COe) Transmitter
  • All combustions with combustion temperatures up to max. 3,092 °F (1,700 °C) (see different models)
  • Die casting aluminum enclosure with electronics, keyboard, up-front display of O₂ and COe*
  • COe measurement
  • Compressed air back-purge with control valve complete with electronics



  • In-situ combustion optimization monitor
  • In-Situ Oxygen and Combustibles (COe) Transmitter
  • Superior Design for Superior Results!
  • Combination of O2 and COe for ideal combustion efficiency
  • Real-time measurements
  • Unique, heated solid electrolyte combustibles sensor
  • Easy access to sensors for fast and simple service


  • Make your combustion process more cost-effective.
  • Get the data to show your organization cares about the environment.


Cement Industry, COe, Gas Turbines / Compressor, IN-SITU, Installers / Boiler Manufacturers, Iron / Steel Industry, O2, Power Plants, Refineries / Petrochem, simple



The MRU OMS 420 Series Transmitters are offered in four different versions: Compact, Remote mount, High-temp, or Ex for hazardous locations.  The OMS 420’s are  the ideal choice to optimize fuel efficiency on combustion sources, with a number of advantages over other transmitters.

  • The addition of our unique combustibles sensor allows safe operation with a lower Excess Air Ration, translating in to higher efficiencies
  • The MRU Combustibles Sensor is accurate and stable even down to 1% oxygen – No dilution is needed.
  • The Flow Guidance Tube design allows the sensor to be mounted near the back of the transmitter to make service fast, easy, and no need for system shutdown.
  • Mounting versatility
  • Available Auto Calibration

Better sensors and design for better performance and reliability

  • Zirconium dioxide O2 sensor has long life, fast response, high stability & low energy consumption
  • Heated Solid Electrolyte COe sensor has high accuracy/sensitivity, fast response, long life, and stable down to 1% oxygen -No dilution air required,
  • Flow Guidance Tube allows easy access to the sensors and are suitable for high dust / particulate or high temperature applications to 3000°F with probe lengths to 6′
  • Optional Auto Calibration
Measuring ranges
COe – Combustibles0 … 1,000 ppm COe (combustibles gas)
O2 – Oxygen0.1 … 25 % (user defined analog output range)
Dimensions and other data
Transmitter outputsTwo (2) 4/20mA and RS485 (Modbus)
FlangeDN65 PN6, Ø 6.5″ (165 mm) for Compact & RT

4″ 150lb ANSI for HT;

4″ 150lb ANSI Flange Adapter for Compact & RT


Response time T90< 10 seconds
Power supply18-24VDC; 90-100 W
Protection classIP 65
Weight> 33lbs (15 kg), depending on probe tube size

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