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:
Jul. 21, 1992
Filed:
Feb. 23, 1990
Charles D Crawford, Burlington, NC (US);
James A King, Jr, Stoneville, NC (US);
John H Randolph, Charlotte, NC (US);
J.A. King & Company, Inc., Greensboro, NC (US);
Major Oil Company, Inc., Greensboro, NC (US);
Abstract
A system for monitoring a storage tank containing a fluid. The system measures the buoyancy force acting on a displacer suspended in a storage tank by means of a load cell. The resulting force acting on the displacer is proportional to the mass of fluid in the tank. A look-up table is first developed by making periodic entries of the resulting load cell output during the initial filling of the tank. This data is then stored in a computer memory. By utilizing this data and interpolating between entries, a very accurate measurement of the fluid mass in the tank is calculated. In addition, by making periodic measurements over time, small leaks can be detected. In the preferred embodiment, the monitor includes an A/D converter located adjacent to the sensor assembly, thereby substantially eliminating measurement errors due to thermoelectric effects. The sensor assembly includes a generally cylindrical displacer extending from near the tank bottom or at least below the lowest level reached by the fluid in the tank to the maximum level reached by the fluid. In one preferred embodiment, the displacer has a tapered cross-section on at least one of its ends to substantially eliminate measurement errors which occur due to changes in fluid temperature.