Patent ID: 9057638
Filing Date: 2015-06-16
Classification: G01F

Abstract:
1. A system for measuring the level of a substance in a container, comprising: an emitting transducer mounted on an inner surface of a body of said container providing a signal generated by a variable frequency oscillator to excite acoustic resonance of an acoustic circuit represented by a container having an empty space filled with a vapor analogous to a capacitor of an acoustic circuit; 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 second tube configured to allow for the addition or removal of said substance in said container without perturbing said tube analogous to said inductor of an acoustic circuit; a sensing transducer mounted on an inner vertical surface of said tube analogous to an inductor measuring amplitude of the signal as it changes as the circuit achieves resonance and as the container is filled or emptied; a cap capping an opening formed at an end of said tube, wherein said cap includes a flexible perimeter connecting the cap to the opening formed at the end of said tube, wherein said cap is configured to move freely as said system resonates 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 resonant frequencies from background noise using correlation functions by referencing the signal generated by the variable frequency oscillator.