METHOD AND APPARATUS FOR MEASURING VELOCITY OF FLOW OF FLUID FLOW

摘要

PROBLEM TO BE SOLVED: To measure a velocity of a flow at low costs highly accurately by measuring a frequency spectrum and a relative phase delay of detected acoustic pulses and measuring an average movement time and a difference of movement times. ;SOLUTION: Two ultrasonic emission/reception converters are arranged at two points PA, PB in a pipe where a fluid flow of a velocity V circulates. Ultrasonic pulses of a considerably shorter duration time than a pass time thereof between two converters are simultaneously emitted from one converter to the other converter. A movement time tv1 in a direction of the flow and a movement time tv2 in the opposite direction are found from arrival times of the signals. The velocity V of the fluid flow is found according to a formula. The tv1 and tv2 must be measured considerably highly accurately. Particularly, a value of Δt=tv2-tv1 must be of a higher accuracy than an accuracy required for the apparatus.;COPYRIGHT: (C)2000,JPO