| 摘要 |
PURPOSE:To improve an accuracy of a carbon monoxide sensor without influence of an oxygen concentration by utilizing an oxygen concentration in gas to be measured by a pump cell. CONSTITUTION:A first space 43a of a hollow part 43 communicates with an outer space of a base 41 via a capillary 45, and gas to be measured is introduced into the space 43a. A carbon monoxide adsorber 61 is filled in a second space 43b, and an oxygen partial pressure of the gas to be measured passed through the adsorber 61 is detected by a first detecting electrode 56. In this case, a pump cell formed together with electrodes 51, 52 by a cell part 42 controls the oxygen concentration of the space 43a by applying a DC current from a power source 52 to the electrodes 51, 52 to substantially remove oxygen gas from the space 43a and to allow the adsorber 61 to adsorb carbon monoxide of the gas to be measured. Then, oxygen gas is introduced into the space 43a, and a time until it reaches the electrode 56 is measured thereby to measure a carbon monoxide concentration. Thus, the carbon monoxide concentration can be accurately measured without influence to the oxygen concentration. |
