The SIRO2 C500+ sensor has the same Nernstian output characteristics as the C700+ sensor.
It is optimised for use in heated probes or sampling systems that use miniature heaters to maintain the sensor at its operating temperature. The thin (1.5 mm) zirconia electrolyte minimises the effect of thermal gradients and transient temperature changes. It is the best choice for oxygen monitoring and control in boilers and power stations
The sensor consists of a solid zirconia ceramic electrochemical cell bonded to an alumina tube.

| Impedance: | between 20kΩ and 100kΩ at 500°C |
| Response time: | less than 2 seconds |
| Sensitivity: | Better than 3 mV |
| Operating Temperature: | From 500°C to 1700°C |
| Diameter: | Ø8 mm Outside, Ø5 mm Bore |
| Length: | Any length up to 1400 mm (2 metres on special order) |