GAS DETECTION ELEMENT

摘要

PURPOSE:To obtain a combustible gas detection element which is highly sensitive at a relatively low working temperature even with a high sensitivity to CH4 gas by use of a gas sensitive body mainly composed of SnO2 and containing SO4<--> within the specified range of proportion. CONSTITUTION:An SnO2 powder is mixed with an SnSO4 powder and after an organic binder is added thereto, the mixture is graded to particles of 100-200mum to make a powder. The powder is pressure-molded into a rectangular parallel piped and sintered in the air. Au or the like is evaporated on the surface of a sintered body to provide a pair of comb-shaped electrodes while a heat generating body made of Pt or the like is provided on the back thereof to obtain a combustible gas detection element. The sintered body is produced from a mixture containing SO<--> 0.05-10wt% by addition of SnSO4. The presence of SO4<--> provides an element which is sufficiently sensitive within a range several tens - a fraction of the lower limit concentration of explosion even with a high sensitivity to CH4 gas.