| 摘要 |
PURPOSE:To obtain a small-sized gas sensing element having high response velocity and large output voltage, by forming an electrode by baking different kinds of electrode paste on the upper and lower surfaces of a sintered body disk having a specific composition and covering said electrode by a porous protective layer. CONSTITUTION:In order to prepare a porcelain composition consisting of (BixLa1-x)2 W3O12 (X=0-0.8), a prescribed quantity of oxide is weighed respectively and said oxide is mixed with pure water by a ball mill for 46hr and filtered and dried. Hereafter, the dried mixture is calcined at 1,200 deg.C for 2hr and is pulverized again by a grinder. Then it is granulated after adding 5% polyvinyl alcohol and is molded by pressing in a rod having 10mm.phi diameter and about 5mm. length. Said rod is sintered 3 at 1,000 deg.C for four hours and hereafter, it is cut into 0.5mm. thickness. Further, a platinum electrode 1 is baked on the one face and hereafter, a silver electrode 2 is baked on the other face and lead wires 4, 4' are connected. Moreover, glass paste is applied as a porous protective layer 6 and the resulting product is baked at 500-700 deg.C. The concentration of reducing gas is known by measuring voltage induced in the sample at the time of flowing the gas. |
