| 摘要 |
In a sensor element 101, a reference gas regulation pump cell 90 pumps in oxygen to the periphery of a reference electrode 42 in which a reference gas is introduced, by the flow of a control current Ip3 between the reference electrode 42 and an outer pump electrode 23 located in a region exposed to a measurement-object gas. An average current density of the reference electrode 42 under the flow of this control current Ip3 is higher than 0 µA/mm 2 and lower than 400 µA/mm 2 . The average current density is preferably not higher than 170 µA/mm 2 . An average value of the control current Ip3 is preferably higher than 1 µA. The outer pump electrode 23 as a measurement-object gas side electrode of the reference gas regulation pump cell 90 may be provided on an outer surface of a layered body (or more specifically, on a second solid electrolyte layer 6). |
