| 摘要 |
PROBLEM TO BE SOLVED: To provide a CO sensor and a CO concentration measuring method capable of accurately measuring the concentration of CO even if the concentration of hydrogen in gas to be measured is changed. SOLUTION: Hydrogen in the gas to be measured introduced into a first measuring chamber 2 through a first diffusion rate limiting part 1 is dissociated, decomposed or reacted by applying first predetermined voltage across a first electrode 7 and a second electrode 8. Protons generated as a result are moved from the first electrode 7 to the second electrode 8 through a first proton conduction layer 5 or, (for example, when the concentration of hydrogen in the gas to be measured is extremely low), protons are moved from the second electrode 8 to the first electrode 7 to control the concentration of hydrogen in the first measuring chamber 2 constant. The gas to be measured thus controlled in the concentration of hydrogen is introduced into a second measuring chamber 4 through a second diffusion rate limiting part 3 and second predetermined voltage is applied across third and fourth electrodes 9 and 10. By this constitution, the concentration of CO in the gas to be measured is calculated on the basis of the value of a current flowing across the third and fourth electrodes 9 and 10 (the limit current value of protons). Or, the concentration of CO in the gas to be measured is calculated on the basis of the electromotive force generated across the third and fourth electrodes 9 and 10. |
