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Screwfit Zirconium Dioxide Oxygen Sensors

SST manufacture the Screwfit zirconium dioxide oxygen sensors, which is ideal for applications in the combustion industry.

The Screwfit zirconium dioxide oxygen sensors have a threaded probe design making it easy to install. Suitable for combustion control within industrial coal/oil/gas/biomass boilers, continuous emission monitoring systems and controlled atmosphere monitoring.

SST’s range of Screwfit zirconium dioxide oxygen sensors use a unique closed loop measurement system. While the sensor continuously measures the oxygen level, a heartbeat signal is also generated providing an immediate warning of any failures.

Their long operating life is due to the non-depleting sensor cell technology. No reference gas is required and easy single point calibration can be performed in any known gas including fresh air.

The oxygen sensor can cope with extreme temperature levels from -100°C up to 250°C and has a rapid response time of less than four seconds. In addition to this, the sensor offers a linear output signal, a lifetime of up to 10 years (depending on the application), and covers an oxygen range from 0.1 to 100% O₂.

All of SST’s zirconia oxygen sensors require interface electronics to operate which SST can provide (see related products below). For high volume applications, we can work with you to design your own electronics, saving you time and money.


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Part Numbering Guide


Heater voltage
    Operating 4.35Vdc +/-; 0.1Vdc (1.85A)
    Standby 2Vdc (0.85A)
Pump impedance at 700°C
Permissible gas temperature -100°C to +250°C
Gas flow rate 0-10 m/s
Repetitive permissible acceleration 5g
Incidental permissible acceleration 30g
Mounting Thread M18 x 1.5


Oxygen pressure range 2mbar-3bar max.
Accuracy 5 mbar max.
Internal operational temp 700°C
Response time (10-90% step)
Warm up time (prior to sensor operation) 60s
Warm up time (from standby) 20s
Output stabilisation time ~ 180s




Molex Mating Connector


Pin Designation
1 Pump (Red)
2 Common (Black)
3 Heater (+) (Yellow)
4 Sense (Blue)
5 Heater (-) (Yellow)


  • Zirconium dioxide technology
  • Requires remote electronics to operate
  • Small sensing element
  • Low weight
  • Integral heating element
  • All stainless steel construction both internally and externally
  • Customer specific designs and connectors
  • Works at high oxygen pressures
  • Compact in size


  • Long life, non-depleting technology
  • No reference gas required creating the ability to measure a wide oxygen range
  • No need for temperature stabilisation
  • Linear output signal
  • Can be used in high pressure and temperature environments
  • Simple recalibration if/when required
  • Full technical and application support available
  • This field is for validation purposes and should be left unchanged.