Any conduit or channel in which the fluid or liquid is flowing with a free surface open to the atmosphere is referred to as an “open channel”. For instance, tunnels, nonpressurized sewers, partially filled pipes, canals, streams, and rivers, all these are Open channels.
There are various techniques which can be used to monitor an open-channel flow. However, depth-related techniques are the most widespread. These techniques are based on the conjecture that one can instantaneously determine the flow rate of liquid by measuring its depth (or head).
Two most commonly used primary devices for measurement of open-channel flows are:
- Weirs and
These two are specifically designed channel shapes which illustrate the flow of water. Selection of a flume or weir type is based upon following factors:
- Type of application
- Flow rate
- Shape of the Channel
- Solids content existing in the water
Open channel flowmeters are typically required for applications such as wastewater treatment and irrigation flows.