Hall effect sensors have arious applications, one of the typical functions of Hall effect sensors is in the automotive industry, where the device has various uses, including in automotive fuel level indicators.
There are two ways that Hall effect sensors are used to measure fuel levels. Firstly, in a vertical float system, a permanent magnet is fixed to the surface of a floating object, while the sensor is fitted to the top of the tank, in line with the magnet.
After filling up your car or vehicle, the floating magnet rises to the top of the tank, bringing the magnetic field towards the sensor and increasing the Hall voltage. As the fuel levels lower, the magnet drops, decreasing the Hall voltage in parallel.
As well as measuring fuel, Hall effect sensors are commonly used to time the speed of rotating parts like wheels and shafts, and are particularly useful in various ‘tachometers’, which measure things like speed of the vehicle and RPM.
Hall effect sensors are particularly useful in conditions where things like water, vibrations, or dirt are present, which would impact upon optical and light sensors. This is why they are particularly effective in industrial applications, as magnetic fields cannot be interrupted by external factors.