| 主权项 |
1. A sensor control apparatus for controlling a gas sensor including a first measurement chamber into which an object gas is introduced, a first oxygen pump cell having a first solid electrolyte layer and paired first electrodes provided on an inside and outside, respectively, of the first measurement chamber, a second measurement chamber in communication with the first measurement chamber, and a second oxygen pump cell having a second solid electrolyte layer and paired second electrodes provided on an inside and outside, respectively, of the second measurement chamber, the sensor control apparatus comprising:
a drive control section programmed to perform drive control for adjusting an oxygen concentration of the object gas introduced into the first measurement chamber by supplying an electric current to the first oxygen pump cell and for applying an operating voltage to the second oxygen pump cell; a preliminary control section programmed to perform, before start of the drive control, preliminary control which supplies a constant current to the second oxygen pump cell over a constant period of time, to thereby control to a constant level an amount of oxygen pumped out from the second measurement chamber to outside of the second measurement chamber; a calculation section programmed to calculate a concentration correspondence value which represents a concentration of a specific gas contained in the object gas, on the basis of the magnitude of current flowing through the second oxygen pump cell to which the operating voltage is applied after the start of the drive control; a storage medium for storing, as correction data common among a plurality of the gas sensors, pattern data which represents a pattern of a time course change in the concentration correspondence value after the drive control is started after the preliminary control which has been set in advance is executed, which pattern data is obtained under a condition where both the preliminary control and the drive control are performed in the presence of a reference gas; a determination section programmed to determine a timing for applying the correction data; and a correction section programmed to correct the concentration correspondence value by applying the correction data to the concentration correspondence value at the timing determined by the determination means, said correction data being applied when the determination section determines that a pattern of a time course change exhibited by the concentration correspondence value after the start of the drive control approximately coincides with the pattern of the time course change represented by the correction data. |
