ULTRASONIC PULSE-PHASE METHOD APPLIED IN ULTRASONIC FLUID-FLOW MEASUREMENTS

A novel pulse phase method for ultrasonic flow measurement in pipes un der pressure is presented. It belongs to a group of direct time measur ement methods. The difference in propagation (transit) time between tw o ultrasonic beams transmitted in upstream and downstream directions a cross the fluid flow is measured. With a goal to achieve an accuracy b etter than 1% each of the transit time intervals is decomposed into tw o intervals. The first interval, called 'coarse', points to an integer number of the ultrasonic signal periods during propagation time, and the second one, called 'fine', points to the rest of its periods. Flui d flow velocity and volume quantity are determined through involving t he calibration function. The main metrological characteristics of the realised fluid flowmeter are determined using available working etalon s. Experiments have shown that the total error of the flowmeter descri bed herein is within the specified accuracy of 1%.