Abstract: An engine oil contamination sensor includes a first sensing electrode and a second sensing electrode. A sensing area is established between the electrodes. The sensor is oriented in an oil pan such that the sensing are is completely submerged in engine oil. A microprocessor is connected to the sensing electrodes and includes a program for determining whether antifreeze is dispersed in the engine oil.

Abstract: A method for determining a level of water contamination in a fuel containing ethanol, including determining the ethanol concentration of the fuel; sensing the resistance of the fuel; determining a resistance limit of the fuel; and comparing the resistance to the resistance limit to provide the level of water contamination. Ethanol concentration is preferably obtained by comparing a measured capacitance to known values in a look-up table. The resistance limit can be determined by multiplying a resistance corresponding to the ethanol concentration by an alarm fraction. The resistance is obtained by a look-up table of resistance values at known water contamination levels. Reporting occurs when the measured resistance is at or below the resistance limit. Alternatively, the measured resistance is normalized with respect to the resistance with no water contamination and reporting occurs when −1.6667*normalized resistance+1.6667 approaches 1.0.

Abstract: A device for sensing oil condition includes an oil condition sensor that includes a first sensing plate separated from a second sensing plate by a spacer. Affixed to the first sensing plate and the second sensing plate is a platinum sensing electrode and a resistance temperature device. The sensing electrodes are separated by a gap that is filled with engine oil when the sensor is installed in an oil pan. A processor connected to the sensor can be used to determine when the engine is experiencing a first stage of oil degradation, a second stage of oil degradation, and a third stage of oil degradation. Each stage of degradation is characterized by a first sensor output signal trend, a second sensor output signal trend, and a third output signal trend, respectively.

Abstract: A sensor and method for measuring the volatility of liquid gasoline by estimating its driveability index includes a sensing element having an interdigitated array of electrically conducting capacitor plates arranged to retain a predetermined volume of gasoline, the volatility of which is to be measured. The sensing element is mounted in a vehicle to be in contact with the flow of gasoline while the engine is running so that a volume certain of gasoline is drawn between and remains within the electrically conducting plates when the engine is turned off. The sensing element is connected to circuitry used to measure the change in capacitance of the sensing element as a function of time while simultaneously measuring the temperature change of the sensing element as the volume of gasoline retained by the sensing element is evaporated over time. The measurements obtained by the circuitry are used in estimating the drivability index of the gasoline.