| 摘要 |
PURPOSE:To obtain oxygen concn. detection output having good linearity in a wide range from an lean region to a rich region, by adjusting diffusion resistance by providing a pair of electrodes opposed to the electrolyte wall parts of two gas stagnation chambers different in the diffusion resistance to gas to be measured. CONSTITUTION:Electrode pairs 11a, 11b, 12a, 12b and 13a, 13b, 14a, 14b are respectively provided on the inner and outer surfaces of the electrolyte walls of gas stagnation chambers 2, 3, which are formed in an oxygen ion conductive solid electrolyte member 1, in a state opposed to each other so as to hold said inner and outer surfaces therebetween and the exhaust gas in an exhaust pipe flows not only in the chamber 2 from an introducing port 4 to diffuse but also in the chamber 3 from an introducing port 5 to diffuse. In a sensor selection state, a pump current flows between electrodes 11a, 11b and oxygen in the chamber 2 is pumped out or pumped in according to the direction of the current and the pump current value is proportional to the concn. of oxygen in the exhaust gas. Therefore, by supplying the pump current making the concn. of oxygen in the chamber 2 constant, the pump current value is proportional to the concn. of oxygen in the exhaust gas in lean and rich regions. |
