| 摘要 |
PURPOSE:To prevent the reaction between platinum and a semiconductor layer and to stabilize the resistance of the element by forming a protecting film on a platinum trimming film, and providing the semiconductor layer on said protecting film. CONSTITUTION:The protecting film of 10-15mu of aluminum cement or beryllia cement is formed on the platinum trimming film. The SnO2 series semiconductor layer is provided on the protecting film to detect the electric resistance of the platinum film. In this constitution of the element, the resistance value is stable, secular change does not occur, the sensitivity to alcohol or smoke is not found (characteristic 10 in the Figure), and the sensitivity to LNG, town gas, and LPG is high. |
