83 Wood Street, California Gully

Victoria 3556, Australia

Email: ceramics@cof.com.au

Phone: +61 3 5446 8151

Simple, robust, entirely ceramic oxygen sensors

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C3M Oxygen Sensors


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The SIRO2 C3M sensor is the second generation of SIRO2 technology offering better mechanical stability, and longer mechanical life. It has the same geometry as the C700 sensor, with one fewer groove for identification purposes.


Parameter Minimum Typical Maximum Unit
Operating temperature † 500 1200 1600 °C
Ramp Rate - - 600 °C/hour
Storage 5 20 50 °C
Parameter Minimum Typical Maximum Unit
Output voltage range 2.0 1130 1600†† mV @ T ≥ 700°C
Output impedance 1.00 2.00 10.00 kΩ @ T ≥ 700°C
Response time 10 40 100 ms @ T ≥ 700°C
Offset Error @ 700°C ⋆ ⋆ - ±2 ±10 mV @ pO2=pO2
Measurement Range
Parameter Minimum Typical Maximum Unit
O2 Atmosphere 10-24 - 1 pO2 @ 700°C
O2 Atmosphere 10-12 - 1 pO2 @ 1300°C
Reference Air 10 40 100 mL/min
Sensor Mechanical
Parameter Minimum Typical Maximum Unit
Outer Diameter 7.85 8.00 8.15 mm
Inner Diameter 4.90 5.05 5.20 mm
Cut Length 300 - 1400 mm ± 3mm
Weight - 11.1 - g/100 mm

† Continuous use of sensor above 1300°C reduces the lifetime of the sensor.

†† Under heavily reducing conditions, an output voltage of greater than 1650 mV may be observed. Readings about 1400 mV or greater than 1600 degrees may result in erroneous readings. Absolute maximum output voltage without damage to the sensor for the given atmosphere of 10-24 oxygen concentration. The sensor will provide an output response above 1130 mV, however lifetime cannot be guaranteed under these operating conditions.

⋆ Response times given here are applicable to most reducing atmospheres. Response times will vary depending on test gas type and may be slower for inert atmospheres.

⋆ ⋆ Offset error should be subtracted from the voltage reading during measurements for high accuracy applications. Also, note that this offset value if temperature dependent and that short hot zones/large thermal gradients across the sensor will contribute to higher offset errors.

The sensor within a probe can be installed anywhere in the kiln or furnace if used at temperatures below 1100°C. For operating temperatures above 1100°C, the probe should hang vertically, to avoid sag and loss of internal electrical contact.