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, 1980
Filed:
Sep. 29, 1978
Kenneth D Lawson, Cataumdet, MA (US);
Neil L Brown, Falmouth, MA (US);
Neil Brown Instruments Systems, Inc., Falmouth, MA (US);
Abstract
An acoustic current meter in which two channels have acoustic paths oriented at right angles to each other to measure orthogonal components of a current velocity. Each channel includes two transducers aimed at an acoustic mirror so that the reflected acoustic signal from each transducer impinges upon the opposite transducer. Periodically, a burst of high frequency acoustic energy is simultaneous emitted by each transducer. A current flowing produces a relative phase shift between the received signals representative of the current velocity. The output signal produced by each of the transducers is mixed with a common reference signal to provide two, low frequency, beat frequency signals having a phase difference proportional to the current velocity. Due to the reduction in frequency, the phase shift is expanded in time with respect to the phase shift of the acoustic signals and may be easily measured.