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:
Dec. 07, 1999
Filed:
Jun. 05, 1997
Martin Hewitt, West Chester, PA (US);
Parker-Hannifin Corporation, Cleveland, OH (US);
Abstract
A multi-frequency ultrasonic liquid level gauging system includes a storage apparatus for storing a volume of liquid and a plurality of ultrasonic transducers. Each transducer introduces a distinct ultrasonic signal into storage apparatus and receives a reflected signal back. A circuit drives and receives signals from the ultrasonic transducers. A processor calculates the liquid level at each of the locations of ultrasonic transducers based on the reflected signal received from each transducer. Transducers are connected in parallel, thereby allowing circuit to communicate to the transducers through a single conductive path. A method of measuring a liquid level in storage apparatus includes emitting a single drive signal to a plurality of ultrasonic signal sources, wherein each source is operable to transmit ultrasonic signals having unique frequencies. The ultrasonic signals are transmitted through liquid and each is reflected at the liquid surface. The reflected signals also have unique frequencies and are communicated to processor. The reflected signals are distinguished and the depth of the liquid level at various storage apparatus locations is calculated from each of the distinguished reflected signals. The depth of liquid is a function of the propagation time of each signal through the liquid.