Dynamic Weight Measurement (Fuel Scale)
Fuel consumption can be measured using a flow meter or gravimetrically. Gravimetric measurements track the weight as it changes with time. The fuel scale is a digital weight scale measuring the weight of a fuel tank as a function of time. As fuel is consumed the weight of the tank decreases at the rate of fuel consumption. The weight is measured continuously and sampled on a consistent time basis, say 60 seconds. The difference in weight between subsequent samples is divided by the time between samples to give the mass consumption rate:
Fuel Consumption Rate = (Weight Sample 1 – Weight Sample 2 ) / period
Fuel weight is recorded and displayed as well as the fuel consumption rate based on a selected periods (ie. 5, 10, 30, 60 seconds). When combined with our dynamometer controller the engine power will be recorded as well. The correlation between engine power and fuel consumption can be seen graphically below. This test was a steady-state approximation of the ECE-R40 test sequence. Fuel consumption rate (fine blue line) increases with engine power (thick line).