The working principle of the fuel tank level gauge is mainly based on buoyancy and electrical signals for measuring fuel volume.
The fuel tank float, also known as the oil level sensor, works mainly based on buoyancy and electrical signals. The float floats on the oil surface by buoyancy, and its position directly reflects the liquid level position. As the oil level changes, the float will drive a sliding potentiometer to move, thereby changing the resistance value. The computer system provides a voltage to the sliding potentiometer and estimates the fuel level by measuring the voltage drop returned, ultimately displaying the data on the car dashboard. This working method enables the fuel tank level gauge to accurately reflect the fuel level inside the tank.
In addition, there is a design based on a sliding potentiometer, which drives the potentiometer to move through a float and uses an ohmmeter to measure the resistance value to reflect the level of oil. However, after long-term use, the resistance value of this sensor will change due to the adhesion of grease, resulting in increased measurement errors and even failure, so its service life is relatively short.