| 摘要 |
PURPOSE:To lessen the deterioration of an oxygen sensor without operating an oxygen pump at all times by providing a hermetic space in which a reference electrode is housed into an oxygen sensor element to accumulate the substantial reference material in the hermetic space having a large volume. CONSTITUTION:The longitudinally plate-shaped oxygen sensor element 1 is made into the construction in which solid electrolyte plates 2-4 each consisting of an oxygen ion conductive solid electrolyte are laminated to form the hermetic space 5 hollowed in the longitudinal direction of the intermediate plate 3. The electrolyte plates 2, 4 are joined to both surfaces of the plate 3 to maintain largely the space 5 in the hermetic state. A heater 6 is provided to the bottom end of the plate 2 and oxygen pump electrodes 9, 10 are disposed between said plate and the heater 6. A reference electrode 7 and a measuring electrode 8 are disposed with the plate 4 in-between. The volume of the hermetic space is increased and the reference material is substantially accumulated in the hermetic space, by which the deterioration of the oxygen sensor is lessened without the need for operating the oxygen pump at all times. |
