Patent ID: 9322697
Filing Date: 2016-04-26
CPC Classification: G01F

Claim Text:
1. A system for measuring the level of a substance in a container, comprising: an emitting transducer providing a signal generated by a variable frequency oscillator to excite acoustic resonance of an acoustic circuit represented by a container having an unfilled space filled with a vapor analogous to a capacitor of an acoustic circuit, and a tube analogous to an inductor of an acoustic circuit, wherein the vapor experiences friction as it moves within the tube, which is analogous to a resistor of an acoustic circuit; a sensing transducer measuring amplitude of the signal as it changes as the circuit achieves resonance and as the container is filled or emptied; a speed of sound transducer configured to emit and detect a signal ping inside said container to determine a speed of sound in said container; and a signal processing unit coupled to the sensing transducer and the variable frequency oscillator driving the emitting transducer, said signal processing unit processing the signal sensed by the sensing transducer to extract it from background noise using correlation functions by referencing the signal generated by the variable frequency oscillator.