Oxygen sensing apparatus and method using electrochemical oxygen pumping action to provide reference gas

摘要

An oxygen sensing apparatus for detecting an oxygen concentration of a gas is disclosed. The apparatus includes a first electrochemical cell having an oxygen-ion conductive solid electrolyte body and a reference and a measuring electrode, for producing an electromotive force which corresponds to the oxygen concentration of the gas. A reference-gas chamber formed around the reference electrode is provided with a reference gas by an oxygen pumping action of the first electrochemical cell. The apparatus further includes a second electrochemical cell including a solid electrolyte body and a pair of electrodes, one disposed in a measurement-gas chamber formed around the measuring electrode, and the other exposed in an external space. The measurement-gas chamber is provided with an oxygen gas by an oxygen pumping action of the second electrochemical cell to feed oxygen from the external space into the measurement-gas chamber. Also disclosed is a method of detecting an oxygen concentration using the above-described apparatus.