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. 12, 1978
Filed:
Jul. 18, 1977
Marco Brandestini, Zurich, CH;
Contraves AG, Zurich, CH;
Abstract
A method and apparatus for determining a change of the flow state of a flowable substance by transmitting ultrasonic or ultrasound waves of constant frequency to a spatial region of the substance, receiving ultrasonic waves backscattered by the substance, converting the backscattered ultrasonic waves into a primary signal which is amplitude- and phase-modulated in accordance with the backscattering and demodulating the primary signal in order to obtain a modulation signal. This modulation signal can be divided into a spectrum of signal components of different frequency and possessing pseudo periods which are defined as the time intervals between successive momentary values of the modulation signal, such momentary values corresponding to one another. The time duration corresponding to a predetermined number of pseudo periods is compared with a predetermined time duration.