Patent ID: 8679312

Claim:
A gas sensor system comprising: a gas sensor; a heater that is used for raising a temperature of the gas sensor to a target temperature; a current control unit; a constant control unit; and an acquisition unit that acquires a corresponding temperature value which is a value corresponding to the temperature of the gas sensor, wherein: the gas sensor comprises: a measurement chamber into which a measurement target gas is introduced: a pump cell comprising, a first outer electrode, a first inner electrode that is exposed to the measurement chamber, and a first solid electrolyte that is interposed between the first outer electrode and the first inner electrode; and an electromotive force cell comprising a second outer electrode, a second inner electrode that is exposed to the measurement chamber, and a second solid electrolyte that is interposed between the second outer electrode and the second inner electrode; the current control unit performs a feedback control on a current flowing through the pump cell in response to a voltage of the electromotive force cell and in accordance with a control constant which characterizes the feedback control; the constant control unit changes the control constant based on the corresponding temperature value; and the constant control unit is configured to adopt: a predetermined first control constant when the corresponding temperature value indicates that the temperature of the gas sensor is within a first temperature range where a threshold temperature lower than the target temperature is an upper limit of the first temperature range and an activating temperature of the gas sensor is a lower limit of the first temperature range; and a predetermined second control constant different from the first control constant when the corresponding temperature value indicates that the temperature of the gas sensor is within a second temperature range, the second temperature range including the target temperature and where a temperature higher than the threshold temperature is a lower limit of the second temperature range, wherein the constant control unit is configured to adopt the first control constant instead of the second control constant when the corresponding temperature value indicates that the temperature of the gas sensor is within a first temperature range, and wherein the predetermined first control constant has a constant, non-changing value over the first temperature range, and the predetermined second control constant has a constant, non-changing value over the second temperature range.