| 摘要 |
PURPOSE:To obtain a highly accurate detecting element, by filling up metallic oxide semiconductors sensing a reducing gas in an airtight insulating cylindrical vessel having opening parts and providing electrodes on both sides of the semiconductors and filling up gas selective filers using oxide catalysts on the outsides of the electrodes. CONSTITUTION:Both ends of an airtight insulating cylindrical vessel 1 made of ceramics, etc. are opened and a gas sensing part 2 consisting essentially of metallic oxide semiconductors varying the resistance value by adsorbing the reducing gas (CO, H2, CH4, etc.), is formed at the central part. A metallic oxide catalyst such as NiO, Co2O3 or a catalyst 4 adding a nobel metallic oxide such as Pd, Pt to said oxide and converting a specific kind of combustible gas into H2O or inactive gas such as CO2 by burning the gas by O2 in the atmosphere, is filled up the outside of both sides electrode 3 of the part 2. The cylindrical vessel is heated by a heater 5. In this manner, the element capable of detecting only aimed gas in the combustible gas mixture selectively with good accuracy, is obtained. |
