GAS SENSOR CONTROLLER

PROBLEM TO BE SOLVED: To provide a gas sensor controller with which it is possible to increase the opportunity of humidity detection by a sensor and carry out gas concentration measurement properly.SOLUTION: A sensor control circuit 50 is applied to an A/F sensor 20 that outputs a limiting current that corresponds to the concentration of a specific gas in a gas to be detected by applying a voltage in a limiting current region. The sensor control circuit 50 comprises: an acquisition unit for acquiring a first current output when a voltage is applied in the limiting current region and a second current output when a voltage is applied in a water decomposition region on a higher voltage side than the limiting current region under a prescribed operating condition where fuel is burned in an engine 10; a humidity estimation unit for estimating the humidity of the gas to be detected, on the basis of a difference between the first current and the second current; and a correction unit for correcting a concentration detection value of the specific gas on the basis of the humidity of the gas to be detected that is estimated by the humidity estimation unit.SELECTED DRAWING: Figure 1 【課題】センサによる湿度検出の機会を増やし、ガス濃度測定を適正に実施することができるガスセンサ制御装置を提供する。【解決手段】センサ制御回路５０は、限界電流域での電圧印加により、被検出ガス中の特定ガスの濃度に応じた限界電流を出力するＡ／Ｆセンサ２０に適用される。また、センサ制御回路５０は、エンジン１０で燃料の燃焼が行われる所定運転状態下において、限界電流域での電圧印加時に出力される第１電流と、限界電流域よりも高電圧側の水分解域での電圧印加時に出力される第２電流とを取得する取得部と、第１電流及び第２電流の差に基づいて、被検出ガスの湿度を推定する湿度推定部と、湿度推定部により推定した被検出ガスの湿度に基づいて、特定ガスの濃度検出値を補正する補正部と、を備える。【選択図】図１