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:
Feb. 18, 1997
Filed:
Jan. 12, 1995
Dennis K Briefer, Marlborough, MA (US);
Anthony T Batista, Stow, MA (US);
Setra Systems, Inc., Acton, MA (US);
Abstract
An apparatus is disclosed for measuring the pressure of a liquid column enclosed within a pressurized tank or cell, and for deriving the height and/or density of the liquid column based on the measured pressure. The apparatus includes a first pressure sensor for differentially measuring the pressure within the cell relative to a reference pressure at a first height, and further includes a second pressure sensor for differentially measuring the pressure within the cell relative to a reference pressure at a second height. A feedback network is operative to match the reference pressure to the pressure within the cell at one of the first and second heights. The feedback network ensures that the sensor detecting the one region is maintained at a zero or null differential pressure condition, enabling the use of a small dynamic range sensor.