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:
Jun. 17, 2003
Filed:
Sep. 08, 2000
Steven M. Vogel, Chesterfield, MO (US);
John A. Sturm, Manchester, MO (US);
Andrew M. Matulek, Beauford, MO (US);
Clayton R. Mason, Decorah, IA (US);
William C. Wolffe, Valley Forge, PA (US);
Other;
Abstract
A self-compensating fluid level sensor is described, including a dual array of capacitive sensors on a dielectric substrate, the dual array of sensors forming multiple sensor pairs. Multiple signal detection circuits including comparators are configured to compare the capacitance of a first sensor pair with a second sensor pair. The internal capacitance comparisons allow the fluid level sensor to compensate for variations in the dielectric of the fluid being measured, as well as for manufacturing and materials variations that affect capacitive sensing. The passive level sensor also provides a platform for providing additional circuitry for providing additional information regarding the liquid, such as liquid composition.