| 摘要 |
PURPOSE:To provide a small size and high reliable gas detecting element which has a fast responsing speed and a high output voltage, by a method wherein the respective electrode materials being different in a type are applied to both surfaces of a specified sintered material, being used as an oxygen ion conductive material, and the sintered material and the electrode are covered with a porous protecting layer. CONSTITUTION:A raw material of a magnetic composition is oxides such as La2O3, WO3 and ZrO3 with a purity of not less than 99.8%, which are weighed so that they are brought to 0.4<=x<=1.0 by a chemical formula of La2(WxZr1-x)2)7, they are mixed by a ball mill for 46hr togetherwith pure water, the mixture is filtered and dried, and after it is temporarily burned at 1,200 deg.C for 2hr, it is repulverized by an attritor. A 5% alcohol liquid is then added to granulate it, the granulation is press-molded 10mm. in diameter and about 5mm. in length, and after the work is sintered at 1,200 deg.C for 1hr, it is cut to 0,5mm. in thickness. After a platinum electrode 2 is baked to one side of a sintered material 3, a silvere electrode 1 is baked to the opposite side thereof, and lead wires 4 and 4' are connected thereto. A glass paste is further coated as a porous protecting layer 6 to produce a baked glass detecting element at 500-700 deg.C. The element has a sufficiently fast answering speed to hydrogen, isobutane or the like, is excellent in returning property, is about linearly increased in a value of an electromotive force with the rise in gas concentration, and has an excellent selectivity to gas. |
