| 摘要 |
PURPOSE:To obtain the titled detecting element stable under various atmospheres at high temp. and having high sensitivity over a range from a low temp. region to a high temp. region, by adding a specific amount of an Rh component to an SnO2 gas sensing component having a surface area, an average crystal size and each crystal distribution respectively residing in a specific range. CONSTITUTION:An SnO2 gas sensing component particle of which the surface area is 1-5m<2>/g, an average crystal size dm is 3,200-800Angstrom and the standard deviation with respect to d<3>N(d) when each crystal size is (d) and the distribution thereof is N(d) is 0.2dm or more is prepared. An aqueous solution of Ru- chloride is added to this particle and the resulting mixture is dried and baked to obtain a gas sensing particle containing 0.4-7pts.wt. Ru component as RuO2 to 100pts.wt. SnO2. A pair of Pt-Rh alloy wires 4 are embedded in this sensing particle to form a pellet 3 which is in turn accommodated in the pierced opening 2 of a substrate 1 while the alloy wires 4 are fixed to long grooves 5 of the substrate 1 by an inorg. adhesive 6 and connected to outlet taking-out pins 7 to obtain a combustion state detecting element. By this method, the element stable under various atmospheres at high temp. and having high sensitivity over a range from a low temp. of 300 deg.C to a high temp. of 900 deg.C is obtained. |
