Australian Oxytrol Systems

C+ Probe

C+ Probe - for atmosphere control in carbon anode baking furnaces

  C+ probe - overview


The C+ probe enables accurate, continuous real-time measurement of oxygen and temperature directly within the carbon anode baking furnace atmosphere. A design feature of the C+ probe is the use of special corrosion resistant sheath and electrodes. These materials have been proven in service to be resistant to the corrosive trace gases commonly found in a carbon anode baking furnace atmosphere. C+ probes have been in service for over one year of continuous use, with excellent accuracy and reliability.


The advantages of accurate measurement of the oxygen content of the furnace atmosphere include:


The C+ probe is based on the SIRO2 zirconia oxygen sensor. This all-ceramic sensor is the world-wide industry standard for controlling furnace atmospheres.

Oxygen range0.001% to 21%
Accuracy10% of reading
Response time<5 seconds
Operating temperature700°C to 1000°C
ConstructionRefractory stainless steel sheath with thermocouple head. Proprietary corrosion resistant electrodes
OutputOxygen signal according to the Nernst equation. Optional K-type or R-type thermocouple
ConnectionsCannon plug, other types available on request
LengthAvailable in 100 mm increments from 300 to 1200 mm


Note that the probe contains brittle ceramic components. Treat it as fragile: do not drop, knock or handle roughly.

The probe can be installed anywhere in the kiln or furnace, provided that the temperature at the tip is between 700°C and 1000°C. The probe will measure the oxygen concentration at the probe tip.

Seal the installation port well enough to avoid atmospheric air from flowing inwards and causing a local variation in the oxygen concentration.


Keep the probe head at a temperature less than 60°C.

Supply clean respirable reference air at a rate of 10 cm3/min to the connection provided on the probe head.

The electrical connections are:

Pin 1Optional thermocouple
Pin 2Optional thermocouple
Pin 3Oxygen sensor internal conductor
Pin 4Oxygen sensor external conductor


The oxygen signal is according to the Nernst equation

pO2 = 0.209 exp(-46.42E/T)


pO2 = oxygen partial pressure in atmospheres
E = oxygen signal in mV
T = temperature in Kelvin


There are no user serviceable parts inside the probe.

Regularly inspect the sensor tip, visible through the gas inlets in the sheath, for dust. If it appears to be clogged, remove excess dust with compressed air or a soft brush. Do not insert hard objects in the gas holes or scrape the sensor tip, as this could damage the electrode material.

Ordering & Information

For further information please enquire Australian Oxytrol Systems or use the online Enquiry Form.

Please note that all prices are in Australian dollars. Please see the Commonwealth Bank currency converter to calculate the price in your currency.