V-Notch Weir Monitor

The V-Notch (triangular) Weirs are typically installed in open channels such as streams to determine discharge (flow rate).
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The V-Notch (triangular) Weirs are typically installed in open channels such as streams to determine discharge (flow rate). The main component is a cylindrical weight suspended from a vibrating wire force transducer. As the water level changes, the changing buoyancy force on the cylinder acts directly on a vibrating transducer.

Product Features
  • Vibrating Wire precision water level sensor
  • Simple in, low cost and robust instrument
  • Accurate and sensitive water level monitoring
  • High resolution monitoring
  • Low maintenance system
  • Range: 300mm
  • Resolution*: 0.025% full scale (minimum)
  • Material: Stainless Steel

*Dependent on readout



The Vibrating Wire V-Notch Weir system has three notch options to suit different water flows and a choice of using manual or remote monitoring.

Manual reading has two options:

  • Manual reading of the optical readout by eye
  • Manual reading of the VW transducer using a VW readout

When using remote reading, the Vibrating Wire transducer is connected to a data acquisition system. Once the user has chosen which notch option is most suitable for a specific project, the weir plate is mounted at the exit of an approach channel or stilling basin through which the flow to be measured is channelled.

The measuring point for the head of water is located upstream of the weir plate and comprises either an optical Stainless Steel scale fixed to the basin wall for manual readings by eye, or a Vibrating Wire transducer suspended in the head of water.


  • Ideally suited to the long term monitoring of dams
  • Drainage systems in dams & tunnels
  • Springs and collects from artesian wells
  • Easy to automate via data acquisition and I-Site and Argus monitoring software

Technical Rating


V-Notch Weir Monitor User Manual

Click here to download [PDF]

V-Notch Weir Monitor Datasheet

Click here to download [PDF]

We will soon be bringing you new and improved datasheets, for now, you can still find all the information you need in this downloadable PDF.




Western Australia

Perth Office

209/396 Scarborough Beach Road
Osborne Park
WA 6017


New South Wales

Sydney Office

Unit 137, 18 Buchanan Street
NSW 2041

t: +61 (0) 8 9284 0244
f: +61 (0) 8 9284 0233
e: info@itmsoil.com.au
  t: 1300 884 542

e: info@itmsoil.com.au