On-board diagnostics system
AssigneeJohnson Matthey Public Limited Company
InventorAndrew Francis CHIFFEY
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Abstract
An on-board diagnostics system for an exhaust system of an internal combustion engine is disclosed. The system comprises one or more ferromagnetic materials and a means for measuring magnetic field strength. Also disclosed is a method for on-board diagnostics of a catalyst component in the exhaust system. The method comprises measuring the magnetic field strength of a ferromagnetic material located in close proximity to the catalyst component and determining whether the ferromagnetic material has been exposed to a temperature above the Curie temperature of the ferromagnetic material, as measured by a decrease in the measured magnetic field strength.
Claims13
An on-board diagnostics system for an exhaust system of an internal combustion engine, the system comprising one or more ferromagnetic materials and a means for measuring magnetic field strength.
A method for on-board diagnostics of a catalyst component in an exhaust system for an internal combustion engine, the method comprising:
- (a) measuring the magnetic field strength of a ferromagnetic material that is located in close proximity to the catalyst component, wherein the ferromagnetic material has a Curie temperature above which the ferromagnetic material loses its ferromagnetic properties;
- and
- (b) determining whether the ferromagnetic material has been exposed to a temperature above the Curie temperature of the ferromagnetic material, as measured by a decrease in the measured magnetic field strength.
Dependencies are inferred from the claim text.