| 摘要 |
PROBLEM TO BE SOLVED: To regulate the inflow of sulfur dioxide and prevent the deterioration of a platinum electrode by forming a pair of ceramic porous bodies having a specified pore diameter on both surfaces of an oxygen ion conductor having a heating means and having a pair of platinum electrodes formed on the surfaces, and laminating a porous body layer containing an oxidizing catalyst on one of the porous bodies. SOLUTION: A pair of platinum electrodes 3 are formed on both surfaces of an oxygen ion conductor 2, and a pair of porous bodies 4 having an average pore diameter of at most 1000Å and a porous body layer 5 containing an oxidizing catalyst thereon are arranged on the electrodes 3. The conductor 2, the platinum electrodes 3, 3, the porous bodies 4, 4, and the porous body layer 5 are successively laminated to form a plate gas sensor. The porous body layer 5 consists of a layer containing the oxidizing catalyst and having permeability and easily passes a gas as O2 or CO, and the oxidizing catalyst exhibits the activity in the passing thereof to perfectly oxidize CO. Since the platinum electrodes of the sensor are thus protected by the porous bodies, an age-based drift such as zero point is extremely minimized, and a sensor having highly reliable characteristic can be provided. |
