| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress reduction in the detection capacity of a contact combustion type gas sensor caused by time-related deterioration. <P>SOLUTION: By controlling switching of a changeover switch SW, either one sensor resistor out of first and second sensor resistors Sn1, Sn2 is selected as an element composing a bridge circuit. Since in the individual sensor resistors Sn1, Sn2, deterioration of a catalyst is not almost generated in a no-power supply state, either one of the sensor resistors Sn1, Sn2 is selectively used and the residual sensor resistor Sn1 or Sn2 can be held at the no-power supply state. As compared with a case that one sensor resistor is continuously used, a time-related deterioration degree of each of the sensor resistors Sn1, Sn2 can be suppressed, so that reduction in the detection capacity of the contact combustion type gas sensor can be suppressed. <P>COPYRIGHT: (C)2013,JPO&INPIT |
