In-Vehicle Engine Coolant Void Fraction and De-aeration Monitoring Using a Computerized Electrical Conductivity Method

Instruments and analytical techniques are described for in-vehicle monitoring of amounts of air (void fraction) in engine coolant systems and for evaluating the performance of degas reservoirs. This method, based on electrical conductivity measurements of flowing air / coolant mixture, provides measurement, acquisition and display of coolant system temperature, pressure, flow rate, instantaneous void fraction and rate of air removal by degas bottle. Embedded temperature compensation equations are used for essentially real time display of the void fraction.