COOKING OVEN WITH MULTI-FUNCTIONAL GAS SENSOR

摘要

A cooking oven in which a ceramic gas sensor is disposed in an exhaust guide guiding air from within the oven chamber toward the exterior of the oven casing and the surface temperature of the ceramic gas sensor is changed to change the sensing characteristic of the sensor, so that the single sensor can sense both of water vapor and soot given off from food being cooked. A voltage source including a stabilized direct current voltage source and a non-stabilized or alternating current voltage source is provided for supplying power to the ceramic gas sensor. In the soot sensing mode, the surface of the ceramic gas sensor is heated by the power supplied from the stabilized direct current voltage source to stabilize the soot sensing characteristic of the sensor. An electronic circuit controlling the cooking operation includes a plurality of amplifiers having different gains which are suitably selected to deal with the humidity sensing mode and the soot sensing mode.