Oxygen Gas Sensor Theory & Care
Theory of Operation
The oxygen probe is a galvanic fuel cell with a gas-permeable Teflon membrane at one end. Any gas that is in contact with the sensor membrane will diffuse through the membrane and dissolve in a thin layer of weak acetic acid gel electrolyte. Oxygen reduces at the gold cathode and lead oxydizes at the anode.
At the cathode:
O2 + 2H2O + 4e- => 4 OH-
At the anode:
2Pb + 4OH- => 2 PbO + 2H2O + 4e-
The flow of electrons from the anode to the sensing cathode via an external electronic circuit is directly proportional to the amount of oxygen in the gas phase and varies linearly with the partial pressure of the oxygen in the gas stream. The electrolyte conducts the ionic current, generated by the migrating OH- groups.
Specifications (Max 250)
Specifications (Obsolete Analytical Industries Probe)
Creation Date: 09/12/2003
Last Modified: 10/2/2003