The fuel level gages currently used in the automotive field have not all satisfying performances. The use of board computers now requires precise measurements of the reserve of fuel to be able to calculate the distance it is possible to do. We propose an hot wire gage with better performances (accuracy, linearity, stability, limited space consumption).
This gage consists of an highly electrically resistant metal wire vertically stretched in the tank and through which we send periodically a pulse of current. Heating of wire due to current changes when it is submerged or not in the liquid.
We shall demonstrate that the difference of the voltage across the terminals of the sensor is proportional to the liquid level.