| 摘要 |
PURPOSE:To detect the concn. of a component concerning the electromotive force of a concn. cell in a fluid by forming one among conductors to a heater generating heat by AC and decreasing the DC resistance value between first and second conductors less than the DC resistance value between the adjacent third and fourth conductors. CONSTITUTION:A cell 17 formed in one body is inserted into a case made of metal to constitute a sensor. Atmosphere enters a hollow part 16. The cell 17 is heated by generating heat by passing AC current to the conductor 6. In this state, DC current is passed between the first and second conductors 2 and 3. Oxygen in a cavity 12 moves in a solid electrolyte 1 toward the conductor 3 from the conductor 2, and is released to the part 16. The electromotive force caused by the oxygen partial pressure difference between the cavity and the hollow part is detected by an electromotive force detector 8. The most part of the current of an oxygen pump flows between the conductors 2 and 3 of small resistance. The current flowing through the third conductor 4 or the fourth conductor 5 is small, and the current of the oxygen pump has a scarce influence to the electromotive force of oxygen concn. cell in which the conductors 4, 5 serve as the electrodes. |
