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:
Oct. 01, 1991
Filed:
May. 30, 1990
Serge Regnault, Paris, FR;
Francis Dunon-Bluteau, Chevilly-La Rue, FR;
Jaeger, Levallois-Perret, FR;
Abstract
The present invention relates to apparatus for measuring the level and/or the volume of liquid contained in the tank. The apparatus being of the type comprising a capacitive probe including at least two generally vertical parallel separate main plates for immersing in the liquid, and capacitance-measuring means having a detection input and a ground, the detection input being connected to a first one of the main plates and the ground being connected to the second main plate, wherein the first plate is surrounded by a guard ring. Furthermore, the present invention measures the level or volume of a liquid by calculating a coefficient K using the expression K=(Cmes-Cair)/(Cimm-Cair); in which Cmes is the measuring capacitance between the first and second plates; Cair is the capacitance of the first plate and the second plate in air; Cimm is the capacitance of the first plate and the second plate when they are totally immersed; and K is defined as the area of the first plate in the liquid divided by the total area of the first plate.