instrumentation & monitoring

Instrumentation > Instruments > Water > V-Notch Weir Monitor

V-Notch Weir Monitor

The V-Notch (triangular) Weirs are typically installed in open channels such as streams to determine discharge (flow rate). 

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

Operation 

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.

Applications 

The Vibrating Wire V-Notch Weir system uses the principle of gravitational discharge of water over a triangular or rectangular notched weir plate.

Typical applications include:
Longterm monitoring of dams
Drainage systems in dams and tunnels
Springs and artesian wells