METHOD OF MINIMIZING THE EFFECT OF RESONANCE FLUCTUATIONS ON THE MEASUREMENT SIGNAL IN ULTRASONIC TRANSMISSION MEASUREMENTS

摘要

The invention concerns a method of minimizing the effect of resonance fluctuations on the measurement signal in ultrasonic transmission measurements on two-phase and multi-phase fluid flows in pipes, an ultrasonic transmitter and detector being fitted to the pipe opposite each other so that the ultrasonic beam passes through the fluid in the pipe. The invention calls for the transmitter frequency to be wobbled between a defined upper and a defined lower limit, the limits being defined such that they include the resonance frequencies for all flow conditions which will occur in practice and the received signal is filtered to minimize the effects of the wobble and allow only the fluid-dependent signals to pass.