Measuring Water Velocity by Ultrasonic Flowmeter

A limited study of a sing-around ultrasonic flowmeter was made in a 2.5-ft (0.76-m) square laboratory channel. Traversing the flow vertically with the meter transducers produced a satisfactory velocity profile. Integration of the profile by manual methods showed an average deviation of −3.4% compared to the bulk flow velocity Q/A measured by a venturi meter in a symmetrical profile for flows ranging from 3 cfs-11.4 cfs (0.08 m³/s 0.32 m³/s). Deviations of +l4% to !6% were found in an unsymmetrical flow caused by a thin vertical plate having a width l0% of the channel width. General operation of the meter was satisfactory, and the sing-around principle appears satisfactory for discharge measurement.