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:
May. 23, 1978
Filed:
Oct. 12, 1976
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 due to the dielectric constant of the fluid, such as aviation fuel, being different from that of air, in which the improvement comprises 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. Programmable digital to analog convertors are utilized to provide a universal apparatus full scale set compensation for containers for the fluid substantially independent of the container configuration for compensating for variation in full scale capacitance of a given container and to provide a universal apparatus zero set compensation for containers for the fluid substantially independent of the container configuration for compensating for variations in zero fluid capacitance of a given container. An up/down counting means together with a digital display is utilized for providing an indication of the fluid quantity, the reference probe signal and the sensing probe signal being preferably summed with the zero set biasing signal in a servo control loop with the counting means for providing the digital display of fluid quantity, the loop being nulled when the counting means output is equivalent to the fluid quantity to provide a container configuration independent real time digital display of fluid quantity within a given container or tank.