| 摘要 |
PROBLEM TO BE SOLVED: To provide a nitrogen oxide sensor for measuring NOx with an improved sensitivity without being affected by an external noise. SOLUTION: A sensor consists of an electromotive force detection type sensor cell 1 that is composed of a reference electrode being active only for oxygen on one surface of an ion-conductive solid electrolyte substrate and a detection electrode that is active for oxygen and NOx being formed on the opposite surface and an electrolytic cell 2 that is composed of an electrolytic electrode that is active for NOx on one surface of the above substrate and a counter electrode being provided on the opposite surface. In this case, the detection electrode of the sensor cell and the electrolytic electrode of the electrolytic ell are joined and current is fed between the electrodes of the electrolytic cell so that the electromotive force of the sensor cell 1 becomes zero and then the concentration of the NOx is calculated from the current value. |
