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:
Mar. 25, 2003
Filed:
Feb. 27, 2001
Charles G. Huss, Shakopee, MN (US);
Mark R. Koosmann, Corcoran, MN (US);
Derrick D. Hongerholt, Eagan, MN (US);
Eric D. Haugen, Farmington, MN (US);
Greg A. Seidel, Eagan, MN (US);
Stephen R. Meyer, Savage, MN (US);
Gary A. Willms, Cottage Grove, MN (US);
Rosemont Aerospace Inc., Burnsville, MN (US);
Abstract
A liquid level sensor used for determining liquid levels in a sealed container includes a heat source bonded to the container, a first temperature sensor mounted on the container adjacent the heat source, and a second temperature sensor mounted on the container spaced from the heat source. The temperatures at the first and second temperature sensors are sensed while the heat source is operating, and the differential in the temperatures is measured and used to control power to the heater. Changes in the differential in temperature between the first and second temperature sensors indicates when the heat conductivity between the first and second temperature sensors changes, due to presence or absence of a liquid in the container at the level of the temperature sensors.