Patent ID: 6590402
Filing Date: 2003-07-08
Classification: G01N

Abstract:
A method for determining dispersed antifreeze contamination of oil within an engine using an oil contamination sensor, wherein the oil has a relatively slow resistance change over the life of the oil, comprising the acts of:allowing the oil to pass through a temperature gradient; measuring the output voltage of the sensor; at least partially based on the output voltage of the sensor, determining whether antifreeze is being dispersed in the oil determining when the oil temperature is within a middle temperature range; determining a threshold voltage value, Vth; determining a first difference value, DV1; determining a second difference value, DV2; determining a third difference value, DV3; comparing the difference values, DV1, DV2, DV3, to the threshold voltage value, Vth; and at least partially based on the comparing act, determining whether antifreeze is being dispersed in the engine oil.