Model OT-3H Natural Gas Oxygen measurement

The OT-3H Natural Gas Oxygen Measurement System accurately monitors trace oxygen levels in a variety of gases at the ppm level.

The transmitter is equipped with two user-selectable oxygen analysis ranges and is acceptable for operation in Class I, Division 2, Groups B, C, and D hazardous environments when used in conjunction with a non-incendive power source.

The OT-3H system is housed in a weatherproof NEMA-4 case. For access to the Micro-fuel Cell and transmitter controls, the front door swings open. The transmitter is equipped with two oxygen analysis ranges (0-100 and 0-1000 ppm) and has an optional heating system.

The OT-3H is designed to work with a variety of Flow Computers, such as TotalFlow or FlowBoss, and the system can be ordered in either AC or DC powered versions.

The Sensor

The heart of the system is Teledyne’s own A-2CNG Microfuel Cell oxygen sensor. This cell is a sealed electrochemical device which translates the amount of oxygen present in a sample into an electrical current. And unlike other sensors on the market, it comes complete with a built-in acid gas scrubber.


  • Two analysis ranges, user selectable, 0-100 and 0-1000 ppm
  • Designed to work with all flow computers in use
  • AC or DC powered versions
  • High sensitivity (0.5% FS)
  • High accuracy (±1% of full scale at constant temperature)
  • Insensitive to flow variations
  • Fast response and recovery
  • Long, life maintenance free Micro-fuel Cell sensor
  • Unaffected by reducing agents (HC’s, CO, SO2, etc.)
  • Easy to calibrate, no zero gas required
  • Rugged NEMA-4 bulkhead mount enclosure
  • Temperature regulation through an internal heater (optional)


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