| 摘要 |
PURPOSE:To suppress the impedance of a combustion detecting element and to decrease the amt. of the costly electrode material to be used by sticking a rhodium film to a platinum electrode formed on the surface of a sintered ceramics constituting the combustion detecting element. CONSTITUTION:A sintered zirconia body 1 is dipped in a soln. contg. platinum prepd. by dissolving platinum chloride in ethanol except a part of the open port on one side thereof and thereafter said body is heat-treated. The sintered body is immersed in a chemical plating liquid of platinum and is then washed and dried to form a platinum film on the inside and outside surface of the body 1; A rhodium soln. prepd. by dissolving 0.5pt.wt. rhodium chloride into 100pts.wt. ethanol is coated on the platinum film and the body is heat-treated at 1,000 deg.C to form platinum electrodes 6, 7 stuck with the rhodium film. MgAl2O4 powder is plasma-sprayed on the surface of the electrode 7, by which a porous ceramic film 8 is formed. |
