| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust gas sensor which can detect the concentration of a component to be detected in an exhaust gas with high accuracy even when the oxygen concentration of the exhaust gas fluctuates. SOLUTION: In an exhaust gas sensor 1, an exhaust gas containing oxygen is introduced to a gap 15 and a counter space 16 on both sides of an oxygen- concentration cell element 4 and the activity of first and second electrodes 11 and 12 arranged on the gap 15 side and a third electrode 13 arranged on the space 16 side are adjusted so that a difference may be produced in the consumption of a component to be detected by oxidation between the gap 15 side and space 16 side. Therefore, an oxygen concentration difference is produced between both sides of the element 4 and a concentration-cell electromotive force is generated based on the oxygen concentration difference. An oxygen pump element 3 pumps oxygen in or up from the gap 15 so that the electromotive force can be maintained at a target value EC of 5mV and the current of the element 3 is fetched as the detected output of the component to be detected. |
