| 摘要 |
PURPOSE:To enable detection of O2 concentration in a wide range with excellent accuracy even at a low temperature by putting a proton-containing medium in a porous ceramic vessel and by providing in the medium an electrode to which a compound, such as metallized prophyrin, having the function of an electron transfer catalyst is attached and a reference electrode. CONSTITUTION:The functional electrode 5 to which a catalyst 4 prepared by metallizing tetraaminophenyl porphyrin or the like with FeCl2, CoCl2 or the like and having the function of an electron transfer catalyst is attached is made. The medium 2 containing proton such as polyacrylic amide is put in the porous ceramic vessel 1, while the electrode 5 and the reference electrode 3 are put in the medium 2. This ceramic vessel 1 is covered with a metallic cover 17 having a plurality of holes 20 and fixed to a housing 11. Next, the housing 11 is fixed to a conduit 18 for exhaust gas (an arrow 19 indicates the flow of gas) with a thread groove part 14. O2 dispersed in the medium 2 is reduced with contact by impressing voltage on the electrode 5 and the current generated in the process of reducing reaction is measured. The current is generated as a function of the density of O2. Thus the device is applied to an air-fuel-ratio sensor and the like having high durability even against high temperature and high accuracy. |
