Detector for carbon monoxide and hydrocarbons in waste gases - is composed of a semiconducting oxide doped with another oxide and located in a holder

摘要

Sensor is composed of a semiconducting oxide which exhibits characteristic changes in conductivity when in contact with an oxidising or reducing gas, and is pref. Cr2O3 or SnO2 which is doped with 0.001-10 mole% of an oxide of a transition metal of group 4 to 6 or with Fe, Ni, Co, Sn, Mg, Ca or Li. For detecting CO the sensor is composed of Cr oxide doped with 2 mole % Ni oxide and for a hydrocarbon is Sn oxide doped with 0.1 mole % Mg oxide. The sensor is suitable for use at 300-700 degrees C and is not affected by the oxygen partial press. or moisture content of the atmos. or inhibited by reducing gases.