Applications of Tuning Fork Resonators for Engine Oil, Fuel, Biodiesel Fuel and Urea Quality Monitoring 2009-01-2639

Based on a Tuning Fork flexural resonator, an innovative, miniaturized and rugged sensor that directly and simultaneously measures a fluid’s dynamic viscosity, density and dielectric constant has been developed. The sensor provides a simultaneous fluid temperature measurement by incorporating a temperature sensor into the sensor assembly. The physical property measurements for viscosity, density and dielectric constant are accomplished by high performance algorithms that provide direct feedback to Engine Control Module (ECM), Urea SCR, fuel and other fluid management systems. Based on these data, realtime modification of engine or system operation can be made to optimize power, efficiency, oil drain management and emissions depending on the fluid and control system that integrates the sensor.

Single parameter sensors like electrical property sensors fail to provide sufficient information to accurately monitor fluid quality or degradation. On the contrary, the tuning fork sensor provides multi parametric analysis to enable effective fluid condition monitoring as its four measured parameters offer a 4 dimensional fluid profile based on their absolute and relative change. This technology is being applied to a variety of fluids such as engine and hydraulic oils, fuels and biofuels, transmission oils and urea.

Several key application examples are presented for discussion in this paper: assessment of fluid quality to make a smarter use of engine oil, fuel quality monitoring and unauthorized fuel identification, and finally monitoring of urea solutions quality.