Minisonic Speed open channel velocity meter

The MiniSonic-Speed open channel velocity meter measures the velocity of a fluid in a river or open channel. It uses ultrasonic transit time as its measurement technique.
Submerged velocity sensors are mounted on both banks in a channel or river to measure the flow velocity. These sensors continuously emit a bi-directional, ultrasonic pulse and measure the time difference in transit speed from one side to the other. The difference in transit speed is directly proportional to the velocity. Having multiple pairs of velocity sensors stacked at different elevations increases the accuracy of the velocity measurement.

Features and benefits

Ability to measure channel widths up to 50 meters. This bi-directional open channel velocity meter measures velocity without the need to construct a weir. It is configurable for a wide range of liquids and flow rates.

Two chord input enables this open channel velocity meter to receive signals simultaneously from two sets of sensors. Multiple chords are often used on the same channel to obtain more precision in the velocity measurement by capturing velocities at different depths.

Unrivaled performance accuracy with velocity measurement accuracy of +/- 0.5%, measurement resolution approximately 0.1 nano second, repeatability up to 0.1% and linearity up to 0.1% depending on application and number of chords.

Rugged aluminium enclosure with an epoxy coating and a high ingress protection rating of IP67, this open channel velocity meter is able to withstand harsh environmental conditions. The backlit display, keypad and mounting bracket facilitate quick and easy installation and setup.

Signal quality index using echo visualisation to verify the signal quality from each chord and identify any distortions. The outcome of corrective actions are also verified advising the operator the problem has been solved.

Connectivity with current, relay and pulsed outputs and MODBUS communication via a RS232 or RS485 serial link, this open channel velocity meter is perfect for integration with instrument control panels and telemetry systems.

Ability to operate with low voltage, this open channel velocity meter can be powered with renewable energy sources such as solar with a backup battery. Power supply required is 9 – 32 Volts DC or 90 – 240 Volts AC.


  • Waste water: velocity measurement at treatment works inlets/outfalls (small channels)
  • Raw water: velocity measurement in irrigation channels and small rivers.
  • Effluent discharge velocity measurement.
  • Hydroelectric power generation: velocity measurements in ducts and partially full pipes.
  • Velocity measurements of partially full pipes in the chemical, food and farming industries.
  • Velocity measurements at V-notch channels, weirs and flumes.