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:
Sep. 09, 2003
Filed:
Jan. 04, 2001
Derrick D. Hongerholt, Eagan, MN (US);
Eric D. Haugen, Farmington, MN (US);
Charles G. Huss, Shakopee, MN (US);
Greg A. Seidel, Eagan, MN (US);
Rosemount Aerospace, Inc., Burnsville, MN (US);
Abstract
A built-in test system for an ultrasonic liquid level sensor that includes a transducer assembly having an ultrasonic transducer, and a switch that will be actuated when the ultrasonic transducer is in intimate contact with a surface of a tank in which level is to be determined. Once the switch is actuated to indicate that the ultrasonic transducer is properly coupled to the surface, a test sequence is initiated to determine that the level of ultrasonic transmissions are above a certain desired threshold for a selected period of time, and after which the circuit looks for echoes to determine the depth of the liquid in the tank. Thereafter, the test sequence is repeated for each cycle of level sensing.