| 摘要 |
PROBLEM TO BE SOLVED: To provide an oxygen concentration measurement method and an oxygen concentration measurement device which are capable of accurate measurement with reduced measurement errors in a wide oxygen concentration range including a high oxygen concentration.SOLUTION: In an oxygen concentration measurement device, a pair of electrodes are provided on an oxygen ion-conductive solid electrolyte layer in which a measurement gas chamber to which measurement gas is to be introduced via a diffusion layer is formed, and one of these electrodes is located in the measurement gas chamber and the another is located in an outside space to form a pumping cell for supplying oxygen gas to the measurement gas chamber from the outside space by oxygen pumping action. In an oxygen concentration measurement method, an application voltage Vp applied to the pumping cell is varied so that a current difference &Dgr;Ip between an estimated current Ip' estimated to flow in accordance with the application voltage Vp and a measurement current Ip of the pumping cell determined in accordance with an oxygen concentration in the measurement gas chamber is kept at a set value, and an oxygen concentration is measured in accordance with the application voltage equalizing the current difference &Dgr;Ip to the set value. |
