| 摘要 |
PROBLEM TO BE SOLVED: To provide an apparatus for detecting a concentration of an oxide gas wherein a utilizing process of a sensor can be detected easily. SOLUTION: In a main process, a record number (n) is set to 1 (S110). A maximum value IP1max and a minimum value IP1min of a first pump current, and a maximum value IP2max and a minimum value IP2min of a second pump current are set to respective initial values (S120), and a timer is started (S130). An element temperature, a Vs (oxygen concentration measurement) voltage, and a first and a second pump currents IP1, IP2 are detected (S140, S145, S150), based on which an NOx concentration is detected (S190). In succeeding S200-S270, when the IP1, IP2 detected in S150 are larger than the IP1max, IP2max or smaller than the IP1min, IP2min, the values are updated. After a predetermined cycle T passes (NO in S280), the IP1max, IP1min, IP2max, IP2min are written to a floppy disk correspondingly to the record number (n) at the time. |
