| 摘要 |
PURPOSE:To obtain an oxygen concn. sensor having good heat resistance and heat conductivity by joining and fixing a cell and heater consisting of ceramic materials having the coefft. of thermal expansion different from each other via an intermediate layer which absorbs and buffers the displacement at the boundary therebetween. CONSTITUTION:Porous electrodes 2, 3 consisting of platinum having the function to adsorb and dissociate O2 are formed to face the surface of a solid electrolyte 1 consisting of Y2O3 stabilized ZrO2. The detecting electrode 2 is exposed into a gas to be inspected and the reference electrode 3 is exposed into a diffusion chamber 5. The chamber 5 is communicated with the gas to be detected via a diffusion hole 4. The O2 in the chamber 5 is adsorbed to the electrode 3 and is ionized when current Ip is passed from the electrode 2 to the electrode 3 while the temp. of the solid electrolyte 1 is at 600-800 deg.C. The ions are pumped out via the electrolyte 1. As a result, electromotive force E is induced between the electrode 3 and the electrode 2. The proportional relation between the oxygen concn. Po in the gas to be inspected and Ip is established when the force E is fed back so as to attain the prescribed value. |
