| 摘要 |
PURPOSE:To form a gas sensor having less change in the lapse of time and having a long life and high reliability by applying a prescribed measurement voltage between a working electrode and a reference electrode, and measuring the remaining current subtracting the background current irrespective of the concn. of the gas to be detected from the current flowing between the working electrode and the counter electrode. CONSTITUTION:A working electrode 2 having gas permeability is provided on one surface of a solid electrolyte 1 which is an oxygen ion conductor and a counter electrode 3 and a reference electrode 4 having likewise gas permeability are provided on the other surface. The side faces of the electrolyte 1 are joined airtightly to a cylinder 5 which is an insulator. An outlet and inlet 10, 11 for gas are provided by ain insulator 51 in one inlet of the cylinder 5. When a prescribed voltage is applied between the electrode 2 and the electrode 3 and, for example, gaseous CO is flowed through a gas introducing port 10, electrochemical reaction takes place on the electrode surfaces respectively, and the electrolytic current proportional to the concn. of the gaseous CO flows between the working electrode and the counter electrode. The concn. of the gaseous CO is measured by using said current. |
