Gas sensor, fuel cell system employing it, and automobile

摘要

A gas sensor in which a heating element is fed with a current of three levels in steps continuously for a specified time. An operating section takes in the voltage across the heating element for each current level after elapsing the specified time and determines the temperature from the voltage across the heating element for the lowest level current. Normalized outputs are also determined by correcting the voltage across the heating element according to a correction formula of temperature and zero point and a correction formula of sensitivity. Humidity is then determined from the difference between the normalized outputs, and the normalized outputs are corrected according to the humidity and a correction formula of humidity. The operating section thus determines the concentration of gas to be detected.