Patent ID: 7237441

Claim:
An ultrasonic fluid measurement instrument comprising: a fluid channel having a width; a measurement part including: an approach channel portion located at an upstream side of said measurement part and extending into said fluid channel to one half of the width of said fluid channel; and a split channel portion including at least one partition board, said at least one partition board dividing said split channel portion into at least two channels that are open at opposite ends to allow fluid to flow therethrough, said split channel portion being located downstream of said approach channel; a pair of ultrasonic transmitter-receivers operable to transmit ultrasonic waves into the fluid flowing through the at least two channels of said split channel portion, and receive the ultrasonic waves from the fluid flowing through the at least two channels of said split channel portion; and an arithmetic unit operable to calculate at least one of flow velocity of the fluid and flow volume of the fluid based on a propagation time of the ultrasonic waves transmitted and received by said pair of ultrasonic transmitter-receivers, wherein: said approach channel portion preliminarily rectifies the fluid prior to the fluid flowing to said split channel portion; said ultrasonic transmitter-receivers are disposed at a side wall of said measurement part and at opposite sides of said split channel portion; and one of said ultrasonic transmitter-receivers is located at an upstream side of said split channel portion and another of said ultrasonic transmitter-receivers is located at a downstream side of said split channel portion.