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:
Feb. 27, 2001
Filed:
Nov. 18, 1997
Peter J. Stein, Hollis, NH (US);
Steven Edmund Euerle, Nahsua, NH (US);
Scientific Solutions, Inc., Hollis, NH (US);
Abstract
A non-invasive elastic wave fluid level sensing system for use in sludge laden environments, including transmitting and receiving transducers mounted on an outer face of a wall of a container for a fluid and along a propagation path for an elastic wave transmitted through the wall of the container wherein the elastic wave has a frequency of less than 5 kHz, more preferably less than about 2 kHz, and most preferably less than 1 kHz. A signal processor determines a change in a characteristic of the elastic wave between when a fluid is present in the container in the region of the propagation path and when a fluid is not present in the container in the region of the propagation path. One embodiment utilizes multiple horizontally oriented transmitting and receiving transducer pairs to detect levels of the fluid in the container. Another uses a vertically oriented transmitting and receiving transducer pair and the characteristic of the elastic wave is dependent upon the proportion of the propagation path along which the fluid is present in the container, thereby indicating the level of the fluid in the container. The detector may include a cross correlation detector for determining the change in the characteristics of the elastic wave, the elastic wave preferably has a frequency of 1000 Hz or lower, and the elastic wave characteristic may be the propagation time of the elastic wave, the amplitude of the received elastic wave or the phase of the received elastic wave.