Abstract Methods for measuring liquid levels and leak rates in a storage tank, using an acoustic transducer and a quasi-static reference device that positions an acoustic target within a predetermined distance range below the surface of the liquid. A method for measuring the height of the surface of a liquid, i.e., liquid level. In a tank comprising the steps of (a) positioning the emitting and receiving acoustic transducers below the surface of the liquid, (b) positioning a plurality of fiducials separated by known distances such that at least two of the fiducials lie below the surface of the liquid, (c) emitting acoustic signals, (d) receiving and measuring the travel times for the reflections of the acoustic signals from the liquid surface and the fiducials, (e) estimating the speed of sound in the liquid using the travel times for the acoustic signals in the liquid between at least two of the fiducials, and (f) calculating the height of the liquid surface by multiplying the speed of sound in the liquid by the travel time from the liquid surface to a known height above the bottom of the liquid, and adding the known height to the product of the speed of sound and travel time.
A method for measuring the height of the surface of a liquid, comprising: (a) positioning acoustic signal means for emitting and receiving acoustic signals below the surface of the liquid; (b) positioning a plurality of fiducials separated by known distances, such that at least two of said fiducials lie below the surface of the liquid; (c) emitting acoustic signals from said acoustic signal means; (d) receiving and measuring the travel times for the reflections of said acoustic signals from the liquid surface and fiducials with said acoustic signal means; (e) estimating the speed of sound in the liquid using the travel times for the acoustic signals in the liquid between at least two of said fiducials; and (f) calculating the height of the liquid surface by multiplying said speed of sound in the liquid by the travel time from said liquid surface to a known height above the bottom of the liquid, and adding said known height to the product of said speed of sound and said travel time.
Claim 2
Independent Claim
169 words
A method for measuring the height of the surface of a liquid, comprising: (a) positioning acoustic signal means for emitting and receiving acoustic signals below the surface of the liquid; (b) positioning a plurality of fiducials separated by known distances, such that at least two of said fiducials lie below the surface of the liquid; (c) emitting acoustic signals from said acoustic signal means; (d) receiving and measuring the travel times for the reflections of said acoustic signals from the liquid surface and fiducials with said acoustic signal means; (e) estimating the speed of sound in the liquid using the travel times for the acoustic signals in the liquid between at least two of said fiducials; and (f) calculating the height of the liquid surface by multiplying said speed of sound in the liquid by the travel time from said liquid surface to a known height above the bottom of the liquid, and adding said known height to the product of said speed of sound and said travel time.
Claim 3
Dependent Claim
49 words
The method of claim 1, wherein the step of positioning said plurality of fiducials includes the step of positioning a quasistatic reference device having a plurality of fiducials separated by known distances, such that at least two of said quasi-static reference fiducials lie below the surface of the liquid.
Claim 4
Dependent Claim
131 words
The method of claim 1, wherein (a) the step of positioning said plurality of fiducials includes the step of positioning a plurality of fixed fiducials separated by known distances, such that at least two of said fixed fiducials lie below the surface of the liquid; (b) the step of positioning said plurality of fiducials includes the step of positioning a quasi-static reference device having a plurality of quasi-fixed fiducials separated by known distances, such that at least two of said quasi-fixed fiducials lie below the surface of the liquid; and (c) the step of estimating the speed of sound in the liquid includes using the travel times for the acoustic signals in the liquid between at least two of said fixed fiducials and between at least two of said quasi-fixed fiducials.