Patent ID: 7441455

Claim:
An apparatus for measuring and indicating the level and/or volume of a liquid stored in a container, said apparatus comprising: a first pair of electrodes mounted in the interior of the container in such a position that both of the electrodes of the first pair are partially or totally immersed in the liquid stored in the container, said pair of electrodes acting as one of the capacitors of a first Wien bridge to modify the output signal generated by the bridge-circuit to, in addition to measuring and indicating the volume of the liquid, also providing an indication of the quality of the liquid in the container and the ratio between two different types of liquid stored in the container; a second pair of electrodes, distinct from the first pair of electrodes, mounted in the interior of the container in such a position that both of the electrodes of the second pair are permanently totally immersed in the liquid, the second pair of electrodes acting as one of the capacitors of a second Wien bridge to modify the output signal generated by the bridge-circuit to create a second output signal which is used as a reference for the calculation of the volume, the quality and the ratio between the two different types of fuel in said container.