| 摘要 |
PURPOSE:To provide an element capable of detecting half-burnt by treating it in a reducing atmosphere above 600 deg.C so that the resistance temperature coefficient thereof can reduce in the atmosphere where a high concentration fuel and air coexist. CONSTITUTION:1pt.wt. of Pt is added to 100pts.wt. of SnO2 in the form of H2PtCl6 is sintered with a Pt electrode in air at 1,050 deg.C after it is buried and molded to form a bulk-shaped combustion state detection element of an N type metal oxide semiconductor. The element is treated in a reducing atmosphere at 900 deg.C for 10min. For the reducing gas herein used, an exhaust gas is obtained by burning a 13A gas, methane 8.8% and C2-C4 heavy hydrocarbon 12% at lambda=0.93. The combustion state detecting element thus treated shows a characteristic as indicated by the broken line 2 when a half-burnt occurs (when air and a fuel gas, a 6C gas, are released from a fully premixing type burner), there is no valley of the resistance value between 650-450 deg.C |
