Greyline AVFM 6.1 Area-Velocity Flow Meter

Measures Velocity and Level to Monitor Flow with a single Ultrasonic Sensor

Ultimate Controller

Measure flow through partially filled pipes, channels, canals, and turnouts without a flume or weir. The AVFM 6.1 uses a submerged ultrasonic sensor to continuously measure both Velocity and Level in the channel. The sensor resists fouling, corrosion and abrasion. The flow meter can be configured with the standard submerged velocity-level sensor or with submerged velocity plus a separate non-contacting ultrasonic level sensor, for highly aerated fluids or those with high concentration of suspended solids. 


View flow rate and total flow on the large backlit LCD display and connect to external devices with three 4-20mA outputs and two control relays. Flow rate, volume, run hours, and diagnostic information available through the optional Modbus RTU serial communications. 


AVFM 6.1 Features

  • No flume or weir required - Submersible ultrasonic sensor measures velocity and level simultaneously to calculate flow, no moving parts to wear, foul or clog. 
  • Built in 5 button keypad - intuitive menu, and large backlit LCD display make the AVFM 6.1 the most operator-friendly area velocity flow meter on the market.
  • Fast, simple, installation and setup.
  • Improved performance in a wider range of operating conditions.
  • View flow rate, velocity, level, totalizer, relay status, and important diagnostic information on the LCD display.
  • Three isolated 4-20mA outputs for flow rate, velocity, and level, and two relay outputs for pulse output or alarm.
  • 6.5 million point data logger for greater flexibility of data monitoring, control, and reporting.
  • Min, Max, and Total Flow data from the last 365 days is available on the LCD display, or download directly to a USB for easy reporting.
  • Monitors flow rate, volume total, run hours, and diagnostic information through only two wires with the optional Modbus RTU serial communication output.

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MicroFlow liquid velocity flow sensor catalogueMicroFlow liquid velocity flow sensor manual

MicroFlow liquid flow velocity case studies


  • Stormwater 
  • Wastewater 
  • Irrigation Water 
  • Effluent 
  • Industrial Wastewater
Product Photos

AVFM pipe flow installation.