Patent ID: 7361258

Claim:
An oxygen sensor for determining the oxygen concentration of a gas, comprising first and second chambers ( 62 , 64 ) formed between first and second oxygen ion conductive cell substrates ( 66 , 68 ) and first and second electrodes ( 68 a , 68 b ) formed on the same plane of the second cell substrate ( 68 ), said first electrode ( 68 a ) being formed on an inside wall of the second chamber ( 64 ) and said second electrode ( 68 b ) being formed outside of the second chamber ( 64 ), wherein the area of the first electrode is at least twofold larger than that of the second electrode, and the sensor comprises means for applying an electric potential in the range of 0.2 V to 1.1 V between the first and second electrodes such that a pump current flows between the first and second electrodes when the sensor is used to determine the concentration of oxygen in a gas, said pump current being a measurement of oxygen concentration.