| 摘要 |
PURPOSE:To accurately detect a rich-side air fuel ratio by admitting air which is much enough to burn unburnt components in exhaust gas at T deg.C to a solid electrolyte through a diffusion rate-determining layer. CONSTITUTION:Electrodes 14-1 and 14-2 are formed on both surfaces of a solid electrolyte main body 12, one electrode 14-2 is positioned on the side of gas to be detected across a diffusion rate-determining layer 16, and the other electrode 14-1 is positioned on an air side. A limit current generated between the electrodes 14-1 and 14-2 is measured to detect the air fuel ratio. An air chamber 24 formed inside the main body 12 is linked with the air through an air intake passage formed of plural small holes 26. Then the ratio S/L of the sectional area of the small area to their length is selected as shown by an inequality, where S is the sectional area of the air intake passage, L the length, I1(rich) the current to be generated between the electrodes 14-1 and 14-2 at the most rich side air fuel ratio required to be measured, and K is a constant. |
