Velocity determining method for fluid in pipe, involves transmitting multiple frequency ultrasonic frequencies into fluid

摘要

A periodic electrical signal is transmitted at a number of frequencies and transduced into an ultrasonic signal. The multiple frequency ultrasonic signal is transmitted at a point in a pipe into fluid flowing in it and ultrasonic energy present in another point in the pipe transduced into electrical energy. The received and transmitted electrical signals are mixed and a frequency representing fluid velocity determined from a sample of this to calculate a fluid velocity. Independent claims are also included for the following: (1) A system for determining velocity of fluid flowing in a pipe; (2) and an apparatus for extracting velocity related information from fluid.