| 摘要 |
PURPOSE:To simply detect the concentration of the nitrogen oxide in the measured gas. CONSTITUTION:The first chamber introducing the atmospheric air and the second and third chambers 5, 4 introducing the measured gas are formed with an oxygen ion conductive solid electrolyte member, the first and second oxygen sensors 26, 25 are provided between the first chamber 3 and the second and third chambers 5, 4, and the first and second oxygen pumps 28, 27 are provided between the second and third chambers 5, 4 and the outside. The second and third chambers 5, 4 are formed with an insulating member 8 cutting off the conduction of oxygen ions, a catalyst 20 decomposing the nitrogen oxide into nitrogen and oxygen is provided on an electrode in the third chamber 4 of the second oxygen pump 27, oxidation catalysts 22, 21 are provided near measured gas introducing holes 2f, 2e of the second and third chambers 5, 4, the first oxygen pump 28 is controlled to make the first oxygen sensor output a preset value, the second oxygen pump 27 is controlled to make the second oxygen sensor output a preset value, and the concentration of the nitrogen oxide is detected by the difference between the control currents of them. |
