Capable of metering diesel fuel, gasoline, kerosene, mineral spirits, Stoddard solvent, and heptane, fuel flow meters measure the rate of fuel flow into an engine, consequently calculating the engine’s current rate of fuel consumption and the remaining amount of fuel left in the tank.
Modern fuel flow meters are computerized, sending data on fuel rate, rotations per minute (RPM) and the amount of fuel left in a tank to a display screen.
Some more complicated transportation devices, such as cars, airplanes, and spacecrafts, use the information collected by the fuel flow meter to communicate information to other parts of the machine; for example, the RPM is communicated to a car’s automatic transmission to trigger shifting into a higher or lower gear. Marine vessels and boats often display fuel flow meter screens on the dashboard so the captain can keep track of how much fuel is being used and is remaining. Fuel flow meters are also used in stationary pumping fuel dispensers, passenger cars, heavy trucks, ship engines,
and aerospace applications. Up until recently fuel flow meters used mechanical measurement tools such as turbine or positive displacement; today, most fuel flow meters use ultrasonic sensors to communicate flow rate data to computerized receptors.
Like most other flow meters, fuel flow meters are made of three parts: the primary device, transducer, and transmitter. These three parts are usually combined so that the flow meter is one complete instrument.
Manufacturers offer fuel flow meters that use various techniques to take a reading.
Thermal mass flow meters take measurements with two sensors that work together. A temperature sensor reference and an active heated sensor take measurements by calculating how much heat loss occurs in the flowing liquid, and thus these flowmeters can determine the flow rate based on this amount.
Another type of flow meter is the Coriolis mass flow meter, which operates on the basis of the Coriolis Effect in which a force is applied to the tube of the fuel flow meter, causing the fluid to rotate because of the direction of the acceleration.
Other kinds of fuel flow meters operate using sound. These are called ultrasonic flow meters and include several types, like Doppler Effect flow meters and time-of-flight flow meters.
Each type of flow meter has specific guidelines that must be followed for proper use. In order for liquid flow meters such as water flow meters to work properly, they must remain full of liquid. Gas or contaminants of any kind can affect the accuracy of flow meters’ readings.