Design of a Microwave Sensor for Fuel Quality Monitoring

The fuel of endothermic engines supplies chemical energy to be transformed into mechanical energy, lubricates precision parts in the components of the fuel system and cools metal surfaces that operate under friction conditions. The characteristics of the diesel fuel must meet these three conditions so that the engine operates reliably. Water is the worst contaminant that affect engine operation. Therefore, fuel control is part of maintenance operations to extend the life of the engine, optimizing performance, preventing breakdowns and reducing fuel consumption and harmful atmospheric emissions. This paper reports the preliminary design of a sensor for real time monitoring of the fuel, integrated in the fuel system. The sensor must be low cost and able to detect anomalies in the fuel and deviations from normal operating conditions with good accuracy. Furthermore, given the aggressive nature of the fuel, the detection must be contactless. In particular, due to the different chemical nature of the fuel based on the geographical area of origin, it was decided to design sensors having detectivity that can be selected in a wide dynamic range. The chosen technology is based on time domain reflectometry and microwave measurements.