| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a measuring device for monitoring residual oxygen in exhaust gas monitoring a state allowing easy carrying out of timely intervention by a remedial measure when there is a defect in the measuring device by an auxiliary procedure. <P>SOLUTION: An oxygen partial pressure p<SB>i</SB>predetermined as a desired value is formed in a reaction chamber 25 by an electrochemical oxygen ion pump driven by an electrical pump current I<SB>p</SB>. A pump current proportional to a flow of oxygen can be used as a measurement parameter for a partial pressure p<SB>m</SB>of the residual oxygen in the exhaust gas or its concentration. During a period N which is a normal operation period, the residual oxygen can be monitored. A lambda probe 1 can be intermittently operated. During operation periods H and L, the oxygen partial pressure p<SB>i</SB>in the reaction chamber mainly indicates a minimum value, or a maximum value. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
