| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a gas concentration detecting apparatus accurately detecting a hydrogen concentration in an exhaust gas in a wide range of exhaust gas environments. <P>SOLUTION: The gas concentration detecting apparatus is provided with: a diffusion resistance layer 82 to be exposed in a measurement object gas; a sensor electrode 92 covered with the diffusion resistance layer 82; a sensor 1 generating an output according to a gas component ratio on a surface of the sensor electrode 92; a pump cell 3 isolating part of the measurement object gas in internal spaces 41 and 42 and pumping up or pumping out oxygen; a sensor cell 5 generating an output according to the gas component ratio in the measurement object gas in the internal spaces 41 and 42; and a sensor 2 acquiring a current value of the pump cell 3 as the output according to the gas component ratio of the measurement object gas when the pump cell 3 is activated, so that the output of the sensor cell 5 comes to a predetermined value. The hydrogen concentration in the measurement object gas is detected based on an output difference i<SB>H2</SB>between a sensor current i1 of the sensor 1 and a sensor current i2 of the sensor 2. <P>COPYRIGHT: (C)2010,JPO&INPIT |
