| 摘要 |
PURPOSE:To measure the concn. of oxygen in combustion exhaust gas with good accuracy over a long period of time, by interposing an intermediate layer between a solid electrolyte and an electrode. CONSTITUTION:A pair of electrodes 2, 4, at least an electrode 4 working as a cathode, provided on a substrate composed of an oxygen ion conductive solid electrolyte 1 is composed of perovskite type composite oxide represented by predetermined formula (wherein Ln is at least one element selected from La, Ce, Pr and Nd, A is at least one element selected from Sr, Ca and Ba, Me is at least one element selected from Ni, Fe, Mn, Cr and V, 0<=x<=1, 0<=y<=1 and delta is an oxygen deficient amount). Electrode lead-out terminals 5, 6 are provided to the electrodes 2, 4 and a gas diffusion layer 7 is provided on the cathode 4 and, further, the outer peripheral side surface of the structure consisting of the electrodes 2, 4, the electrolyte 1 and the diffusion layer 7 is brought to a gas impervious state. Furthermore, an intermediate layer 3 composed of an oxygen ion conductor non-reactive with both of the electrolyte 1 and the electrodes 2, 4 is interposed. By this method, the concn. of oxygen in combustion exhaust gas can be measured with good accuracy over a long period of time. |
