The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 1993
Filed:
Jan. 30, 1992
Joseph W Maresca, Jr, Sunnyvale, CA (US);
James W Starr, Bound Brook, NJ (US);
Christopher P Wilson, La Honda, CA (US);
Other;
Abstract
A method for measuring the temperature-compensated change in the height of a surface of a liquid. The method positions an acoustic signal transducer for emitting and receiving acoustic signals below the surface of the liquid, positions a quasi-static reference device with a fiducial such that the fiducial lies within a predetermined range below the surface of the liquid, and positions one or more fiducials below the surface of the liquid to establish points separated by known distances. The transducer emits acoustic signals, and receives their reflections. The travel times of the reflections from the liquid surface and the fiducials are used to calculate changes in travel times during the measurement period, to estimate the speed of sound in the liquid, to correct for temperature-induced changes in the travel times, and to obtain a temperature-compensated change in travel time to the liquid surface. The temperature-compensated change in the height of the surface of the liquid during the measurement period is calculated using the product of the estimate of the speed of sound in the liquid and the temperature-compensated change in travel time to the liquid surface. The presence of a leak in a storage tank may be detected by converting the temperature-compensated change in the height of the surface of the liquid to temperature-compensated volume change using the known shape of the tank and liquid height, and then comparing the temperature-compensated volume change to a threshold value to determine whether the tank is leaking.