Method for ultrasonic flow-rate metering and arrangement for carrying out the method

摘要

In the method according to the invention, an ultrasonic transmission section extends through a flowing liquid and is alternately operated in the flow direction and against the flow direction. In this arrangement, the respectively corresponding delay times T1 and T2 of the ultrasonic waves are measured, and a computing circuit is used to calculate the rate of flow of the liquid from their difference with the aid of a prescribed equation. The mean value T0 of the two delay times T1 and T2 is likewise determined and supplied to a computing circuit (13) which determines a correction value K corresponding to the mean value T0. This correction value K is combined with the measured value for the rate of flow in such a way as to eliminate the influence of the sound velocity on the measured value of the rate of flow. <IMAGE>