초록 ▼

An oil deterioration and contamination sensor includes a housing, a substrate with a first capacitive plate mounted within the housing, a second capacitive plate mounted to the housing close to the first capacitive plate, and a total reference capacitor which includes an external fixed reference cap

An oil deterioration and contamination sensor includes a housing, a substrate with a first capacitive plate mounted within the housing, a second capacitive plate mounted to the housing close to the first capacitive plate, and a total reference capacitor which includes an external fixed reference capacitor. The second capacitive plate is mounted to the housing such that at least one fluid including oil freely circulates within a gap between the first and second capacitive plates thereby defining an oil deterioration and contamination sensor capacitor. The respective capacitances of the oil deterioration and contamination capacitor and the total reference capacitor provide an indication of a dielectric constant of the at least one fluid including oil within the gap. The sensor also includes circuitry for generating the indication of a dielectric constant and oil contamination detection circuitry adapted to receive and process the indication of a dielectric constant and to generate an indication of oil contamination when a dielectric constant of the at least one fluid including oil exceeds a predetermined value or exceeds a predetermined value at a rate of dielectric constant change in excess of a maximum ordinary rate of oil dielectric constant change.

대표청구항 ▼

[ What is claimed is:] [1.] A capacitive oil deterioration and contamination sensor comprising:a threaded metal housing having an inner end for threading into an oil pan of an automobile or other engine, said inner end including supports attached thereto;a heat-conducting substrate mounted within sa

[ What is claimed is:] [1.] A capacitive oil deterioration and contamination sensor comprising:a threaded metal housing having an inner end for threading into an oil pan of an automobile or other engine, said inner end including supports attached thereto;a heat-conducting substrate mounted within said inner end and insulated from said housing, said substrate including an inner surface and an outer surface and a first capacitive plate on said outer surface;a second capacitive plate mounted to said housing by said supports close to but apart from said first capacitive plate such that at least one fluid including oil freely circulates within a gap between said first and second capacitive plates, said first and second capacitive plates defining an oil deterioration and contamination sensor capacitor;a total reference capacitor including an external fixed reference capacitor, said oil deterioration and contamination sensor capacitor and said total reference capacitor providing an indication of a dielectric constant of said at least one fluid including oil within said gap;circuitry for generating said indication of a dielectric constant utilizing capacitances of said oil deterioration and contamination sensor capacitor and said total reference capacitor;a temperature sensitive resistive element thermally connected to said inner surface of said substrate for providing a temperature adjustment to said indication of a dielectric constant in response to a temperature of said at least one fluid including oil; andoil contamination detection circuitry adapted to receive and process said indication of a dielectric constant and to generate an indication of oil contamination when a dielectric constant of said at least one fluid including oil exceeds a predetermined value at a rate of dielectric constant change in excess of a maximum ordinary rate of oil dielectric constant change.