| 摘要 |
PURPOSE: To exclude the effect of the interference gas and effectively detect the target gas by applying a catalyst layer selectively oxidizing the interference gas not only to the current collector of a detecting electrode but also to a counter electrode. CONSTITUTION: A detecting electrode 4 is covered with a catalyst layer 5 to selectively oxidize the interference gas into the carbon dioxide having little coherence, and the generation of electromotive force via the reaction with the carbon monoxide gas can be prevented. When only the detecting electrode 4 is covered, an electromotive force difference is generated by the reaction with the carbon monoxide gas on a counter electrode 2, and interference cannot be sufficiently excluded. The effect is large when gold or platinum is used as a current collector 4 in particular, the direction of the electromotive force by the carbon monoxide gas becomes opposite to that for the NO gas, and the situation is deteriorated. The counter electrode 2 is also covered with the oxidation catalyst layer 5, the carbon monoxide gas concentrations on the surfaces of both electrodes 4, 5 are made nearly zero, and the electromotive force difference caused by the carbon monoxide gas is not generated. |
