| 摘要 |
PURPOSE:To impart self-diagnostic function for preventing erroneous measurement to a limit current type oxygen sensor for measuring the concn. of oxygen in an atmosphere. CONSTITUTION:The current generated in a main electrode film 2a in such a case that oxygen flows in (or flows out of) an oxygen diffusion passage 5 through an oxygen ion conductive solid electrolyte plate 1 by the operation of an auxiliary electrode film 7b is compared with the current generated in the main electrode film 2a when the auxiliary electrode film 7b is not operated. When a sensor is deteriorated, the ratio of both currents becomes a value different from a use initial value and, therefore, the deterioration of the sensor can be detected. |
