Systems for monitoring the composition of exhaust gases
AssigneeNational Research Development Corporation
InventorsJack Graham Firth, Thomas Alwyn Jones, Brenda Rimmington
Life of this patent
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Abstract
In a system for monitoring the composition of exhaust gases from an internal combustion engine, a gas-sensitive resistor consisting of gallium oxide is exposed to the gases and is maintained at a substantially constant temperature above that of the gases. A signal is generated dependent on the resistance of the resistor, which varies monotonically with the air/fuel ratio of the inlet mixture, this signal being usable in a system for automatically controlling the composition of the inlet mixture.
Claims5
A system for monitoring the composition of exhaust gases emitted from an apparatus for the controlled combustion of carbonaceous fuel, the system comprising:
- a gas-sensitive resistor consisting essentially of gallium oxide;
- means mounting said resistor for exposure to the exhaust gases in operation of the apparatus;
- means for maintaining said resistor at a substantially constant temperature above that of the exhaust gases to which said resistor is exposed;
- and
- means for generating a signal dependent on the resistance of said resistor.
A device for use in a system for monitoring the composition of exhaust gases emitted from an apparatus for the controlled combustion of carbonaceous fuel, the device comprising:
- a gas-sensitive resistor consisting essentially of gallium oxide exposed for contact with a gaseous environment;
- and
- an electric resistance heater closely juxtaposed with said resistor and operable to heat it to a temperature of at least 900.degree. C.
Dependencies are inferred from the claim text.