Multichannel ultrasonic flowmeter for horizontal average flow rate in open channel or drain

摘要

The flowmeter employs a multiple transducer structure with a section in the form of a ring of piezoceramic for measurement of the speed of flow through the pipe (8), and a tapered section of piezoceramic for measurement of the propagation path of the ultrasonic waves. The distance (l) between the transducer sections, adjustable by movement of the housing (7c) of the tapered section, is chosen greater than, or equal to, twice the product of absolute time interval measurement error and maximum speed of ultrasound in water, divided by the allowed relative spacing error between the primary transducer section and a third section on the opposite side of the channel.