| 摘要 |
PURPOSE:To improve a gas sensitivity and to detect methane at relatively low temp. by adding Ge or Th to ZnO containing sulfuric acid ion. CONSTITUTION:Zinc sulfate is added to zinc oxide for incorporating the sulfuric acid ion, and furthermore germanium oxide (GeO2) and thorium oxide (ThO2) are added individually or combinedly and then mixed, press formed and calcined in air to manufacture a sintered body. A pair of electrodes is formed to the sintered body to obtain a gas detecting element. The most suitable quantity of sulfuric acid ion to be added and the total quantity of GeO2 and ThO2 are 0.005-10.0wt%, and 0.1-50mol% respectively basing on ZnO in consideration of the adding effect. The gas detecting element constituted in such a way can detect gaseous methane, which has been regarded as difficult to detect the trace quantity without using a noble metal catalyzer, at relatively low heating temp. of 400 deg.C, and the change of resistance value of the element in the lapse of time is small. |
