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. 13, 1979
Filed:
Dec. 12, 1977
Geoffrey S Hedrick, Malvern, PA (US);
Other;
Abstract
An improved fluid quantity indicator, such as for aviation fuel, of the type utilizing capacitive type sensing probes in which a capacitance change occurs proportional to the amount of fluid in a tank or container due to the dielectric constant of the fluid being different from that of air, in which the improvement comprises microprocessor control means for providing display and totalizing control in conjunction with automatic compensation for the zero fluid capacitance variation in a tank and automatic adjustment of the fluid full scale reading for variation in fluid tank capacitance. The microprocessor controls two independent digital servo loops, one of which is nulled when the microprocessor output is equivalent to the fluid quantity for providing a container configuration independent real time digital display of fluid quantity within a given container, and the other of which is nulled when an in-phase signal of equivalent magnitude and opposite sense to cancel out the real component leakage present across the sensing probes is provided. In addition, the microprocessor may be coupled to another microprocessor which functions to total the signals from a plurality of containers or tanks on board the aircraft to provide a total display of fluid on board.