| 摘要 |
PURPOSE:To measure an air fuel ratio with high accuracy over a wide element temperature range by without being affected by the temperature of an atmosphere to be measured by bringing either of a couple of electrodes which constitute an oxygen concentration detecting means into contact with part of an oxygen ion conductor. CONSTITUTION:An air fuel ratio sensor 1 is so constituted that either of the couple of electrodes 12 and 13 constituting an oxygen sensor cell 14 as the oxygen concentration detecting means, i.e. electrode 12 extends leftward in a figure to contact part of the oxygen ion conductor 2 constituting an oxygen cell sensor 5 as the oxygen ion conducting means. In this case, part of an inside pump electrode 3 is put close to the electrode 12 so as to reduce the mutual operation between an outside pump electrode 24 and the electrode 12. Thus, a resistance used as the comparative resistance of metal oxide is substituted with the internal resistance of the oxygen ion conductor 2, so there is no influence of the temperature of the atmosphere to be measured and the air fuel ratio is accurately measured over the wide element temperature range. |
