CAPACITIVE OIL DETERIORATION AND CONTAMINATION SENSOR

摘要

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.