| 摘要 |
<P>PROBLEM TO BE SOLVED: To precisely detect the concentration of the specific gas component in a gas to be detected. <P>SOLUTION: A gas concentration sensor 100 includes a pump cell (first cell) 110 for discharging or pumping up oxygen in the exhaust gas introduced into a first chamber 144, a sensor cell (second cell) 130 for detecting the concentration of NOx from the gas after having passed through the pump cell 110 and a monitor cell 120 producing the output corresponding to the concentration of oxygen in a second chamber 146. A microcomputer 170 variably controls the voltage applied to the pump cell corresponding to the current value of the pump cell on the basis of preliminarily prescribed applied voltage characteristics. Especially, the microcomputer 170 corrects the applied voltage characteristics of the pump cell on the basis of the electric current of the monitor cell and controls the applied voltage of the pump cell 110 on the basis of the corrected applied voltage characteristics. <P>COPYRIGHT: (C)2011,JPO&INPIT |
