3.3. Fuel level monitoring
To ensure that the unit can operate safely with an even layer of fuel above the transducer the design utilizes float switches (Fig.5). An upper float switch sends a signal to a main module to actuate the fuel addition servo when the fuel level (h) goes below a predetermined height currently set at 4cm (Table 3 and Section 5). In a future implementation, the top level float switch will be replaced with a digital level monitor to provide a better control loop signal. If the fuel reservoir runs out, the lower float controlled switch triggers the main module to shut off power to avoid a fire hazard and damage to the transducer.