The informativity of the received signal exciting a circular resonator by bursts

Abstract

The received signal envelope in circular resonator – pipe, when transmitter is excited by bursts is researched in this article. This is a complicated function U(f, t) of the time t and filling frequency f carrying the information about wave attenuation. Exciting the antisymmetric Lamb waves of zero order on the pipe wall, the sediment amount can be set from their attenuation. The envelope of the received signal is stored and saved by changing the filling frequency of the exciting transmitter bursts in steps. So, U(f, t) makes two-dimensional array. Information about the amount of sediments is obtained performing two-dimensional Fourier transform of the envelope U(f, t). It reflects in the rational size of the peaks of Fourier image. The optimal measurement interval, taking into account the first waves, rotated 2-3 times about the pipe is proposed. The further waves are not used because of too small amplitude. The experiment results and informative Fourier image fragments are given. The recurrence of the results is checked and evaluated having differently orientated the transducers while the multiplex measurement in the same pipe cut. Ill. 5, ref. 6.