| 摘要 |
Disclosed is a gas sensor comprising a main pumping cell (26) for pumping-processing oxygen contained in a measurement gas introduced into a first chamber (18), an auxiliary pumping cell (52) for pumping-processing oxygen contained in the measurement gas introduced into a second chamber (20), a measuring pumping cell (60) for pumping-processing oxygen in the measurement gas introduced via a third diffusion rate-determining section (58), an ammeter (64) for detecting a pumping current generated depending on an amount of oxygen pumping-processed by the measuring pumping cell (60), a heater (66) for heating at least the main pumping cell (26), the auxiliary pumping cell (52), and the measuring pumping cell (60) to a predetermined temperature, an impedance-detecting circuit (70) for detecting an impedance between an inner pumping electrode (22) and an auxiliary pumping electrode (50), and a heater control circuit (72) for controlling electric power application to the heater (66) on the basis of a value of the impedance detected by the impedance-detecting circuit (70). Accordingly, it is possible to realize suppression of variation in detection output which would be otherwise caused depending on the measurement gas temperature and a high S/N ratio of detection output. <IMAGE> |
