CORROSION POTENTIAL SENSOR

摘要

PROBLEM TO BE SOLVED: To provide a corrosion potential sensor capable of preventing entry of water into an interior even if brazed portions have faults.SOLUTION: A corrosion potential sensor 1 is configured so that a cylindrical metallic casing 3 is brazing-bonded to an end portion of an electrical insulator 2 having a closed tip end and in which a platinum black electrode 5 is arranged in a tip end portion within the electric insulator 2. An A/AgO sintered powder layer 6 is arranged within the electrical insulator 2, a core wire 7 connected to the platinum black electrode 5 penetrates the A/AgO sintered powder layer 6 to be connected to a core wire 12. A reactor-water-entry-route forming member 9 is arranged within the metallic casing 3 and attached to an end face of the electrical insulator 2. MgO powder 10 is injected between the reactor-water-entry-route forming member 9 and the metallic casing 3. If reactor water 23 enters through cracks generated in brazed portions of the electrical insulator 2 and the metallic casing 3, the MgO powder 10 absorbs this reactor water 23 to generate Mg(OH). The Mg(OH)closes the cracks to prevent entry of the reactor water 23 into the sensor 1.