In which situation is it most appropriate to use a V-Notch Weir?

Using a V-Notch Weir is most appropriate in situations where flow is low. This type of weir is designed to provide highly accurate flow measurements at lower flow rates due to its geometry, which allows for a highly sensitive response to changes in flow. The V-shape creates a smaller opening that allows the water to flow over the weir in a thin sheet, resulting in a more precise measurement of flow.

In low flow situations, other flow measurement methods may struggle with accuracy because of turbulence or other factors that affect water movement. The V-Notch Weir minimizes these issues by ensuring a smooth flow and a consistent relationship between the height of the water above the weir and the flow rate. This makes it ideal for applications in water measurement that require precision, especially when dealing with low volumes of flow.