The fuel gauge is the device on a vehicle indicating the amount of fuel left in the tank. In a car, the gauge is usually on the dashboard, so that the driver can tell when it is necessary to refill the tank with petrol (gas). It is advised that only a certified mechanic should repair any part of a car or other vehicle. An untrained person attempting to fix a fuel gauge may cause further damage to the vehicle.
Fuel gauges work in a number of different ways, and there are numerous reasons why a fuel gauge may have stopped working. However, on most cars, the fuel gauge consists of two simple parts. The first is a float in the petrol (gas) tank, which is attached to a variable resistor. The resistor is held in a circuit. As the float falls to the bottom of the tank, the resistance of the variable resistor increases, as the length of the coil of wire that the current (produced by the battery) has to pass through increases, and hence the probability of collisions of electrons with metal ions in the wire increases. The current in the circuit is inversely proportional to the resistance of the circuit and hence decreases, and the current is what the dial on the dashboard measures. Correctly calibrated, the dial shows the tank as "empty" when the current through the circuit is sufficiently small. This system may break due to a number of factors:
The battery is flat.
The float has detached from the variable resistor.
The circuit has broken, perhaps due to age.
The float has become stuck in one position.
The ammeter (which measures the current) has broken.
Only a trained mechanic can fix most of these problems. Due to the proximity of electrical currents and petrol, an untrained person attempting to fix a fuel gauge may cause problems leading to an explosion.
The source of this information was en.wikipedia.org/wiki/Fuel_gauge
Fuel gauges work in a number of different ways, and there are numerous reasons why a fuel gauge may have stopped working. However, on most cars, the fuel gauge consists of two simple parts. The first is a float in the petrol (gas) tank, which is attached to a variable resistor. The resistor is held in a circuit. As the float falls to the bottom of the tank, the resistance of the variable resistor increases, as the length of the coil of wire that the current (produced by the battery) has to pass through increases, and hence the probability of collisions of electrons with metal ions in the wire increases. The current in the circuit is inversely proportional to the resistance of the circuit and hence decreases, and the current is what the dial on the dashboard measures. Correctly calibrated, the dial shows the tank as "empty" when the current through the circuit is sufficiently small. This system may break due to a number of factors:
The battery is flat.
The float has detached from the variable resistor.
The circuit has broken, perhaps due to age.
The float has become stuck in one position.
The ammeter (which measures the current) has broken.
Only a trained mechanic can fix most of these problems. Due to the proximity of electrical currents and petrol, an untrained person attempting to fix a fuel gauge may cause problems leading to an explosion.
The source of this information was en.wikipedia.org/wiki/Fuel_gauge
