| 摘要 |
PURPOSE:To simplify the measuring system and to make measurement with good responsiveness by determining humidity in accordance with the current value at the inflection point of the 1st threshold current value limited according to the oxygen concn. in a gas to be measured and the 2nd threshold current value limited according to the humidity and at least either of the 1st and 2nd threshold current values. CONSTITUTION:The oxygen sensor 1 is disposed in the gas to be measured. The oxygen in an electrode part 13a coated with a glaze layer 15 is ionized to oxygen ions when a voltage is impressed between a positive electrode 12 and a negative electrode 13. The oxygen in the gas to be measured is then pumped according to the voltage impression from the electrode 13 to the electrode 12. Only the electrode part 13a of the electrode 13 is locally heated at this time and the connecting part 13b is not heated as sufficiently as to indicate an oxygen ion conductivity and, therefore, the oxygen diffuses from the connecting part 13b into the electrode part 13a coated with the layer 15. The humidity is determined in accordance with the current value at the inflection point of the 1at threshold current value limited according to the oxygen concn. in the gas to be measured and the 2nd threshold current value limited according to the humidity and at least either of the 1st and 2nd threshold current values. |
