| 摘要 |
PURPOSE:To shorten the initial erroneous operation time after current supply is re-opened and to enhance sensitivity and a response speed to CH4 or isobutane while lowering sensitivity to obstruction gas, by providing a pair of electrodes to a gas sensor prepared by adding a small amount of Pd and, further, a small amount of Pt to SnO2. CONSTITUTION:A semiconductor 1 comprising metal oxide wherein 0.1- 0.5pts.wt. of Pd and, further, 0.01-0.06pts.wt. of Pt are added to 100pts.wt. of SnO2 and the addition wt. ratio of Pd and Pt is 15:1-3:1 is molded and a pair of noble metal electrodes 2, 3 also used as heaters are formed on said semiconductor 1. A current is supplied to the electrodes 2, 3 of this apparatus to heat the same to 400 deg.C and gas is detected at this temp. By this method, an element high in sensitivity to CH4 or isobutane, suppressed in sensitivity to obstruction gas such as H2 or alcohol, having good response speed and shortened in the erroneous operation time at the initial period of current supply is obtained. |
