| 摘要 |
PROBLEM TO BE SOLVED: To improve durability by preventing accuracy deterioration of a fall in a detection electric current value or the like by a change with time through activation of a catalyst function of a detection electrode. SOLUTION: A gas sensor is provided with electrode activation means 100 which activate a detection electrode 50 in a measurement pump cell 54. The electrode activation means 100 comprises an alternating current supply means 102 which selectively sends an alternating current between the detection electrode 50 and a standard electrode 38, and a second switching circuit 108 which selectively stops action of a main pump cell 34, and a third switching circuit 110 which selectively stops action of an assistant pump cell 62. The alternating current supply means 102 is constituted of an alternating current power supply 104 which sends an alternating current between the detection electrode 50 and the standard electrode 38, and a first switching circuit 106 which performs selective switching between a direct current power supply 56 and the alternating current power supply 104 as a power supply to be connected to the pump cell for measurement 54. |
