| 摘要 |
PURPOSE:To obtain an element excellent in the safety and durability which is capable of detecting nitrogen oxides with a high sensitivity by covering a pair of electrodes provided on the surface of an insulating substrate with a semiconductor thin film having In2O3 mixed with a specified rate of ZnO to measure changes in the electric resistance. CONSTITUTION:A sufficiently thick gold paste is screen printed and fired to form a pair of comb-shaped electrodes 2 and 3 having teeth 4 respectively on the surface of insulating substrate 1 made of alumina or the like. A metal oxide semiconductor thin film 11 having In2O3 mixed with ZnO at a rate by weight of 1-5% is formed by a high frequency sputtering covering the electrodes 2 and 3. Leads 6 and 7 are connected respectively to linking sections 5 of the teeth 4 of the electrodes 2 and 3. The detection element 10 thus obtained has the leads 6 and 7 welded on stems 13a and 13b of a mount base 12, a heater 14 is wound on the circumference thereof 10 and both terminals thereof are connected to the stems 13c and 13d. Thus, an element excellent in the durability which is capable of detecting nitrogen oxides with a high sensitivity is obtained. |
