The weir should be between 0.03 and 0.08 inches (0.8 to 2 mm) thick in the V. If the bulk of the weir is thicker than 0.08 inch, the downstream edge of the V can be chamfered at an angle greater than 45 …

In this guide we'll explain how V notch weirs work, their pros and cons, and the equations involved in V notch weir design.

Use this V Notch calculator to calculate the flow rate of a triangular weir by entering hydraulic head and notch angle.

The V-notch weir is a precise instrument used for measuring the flow rate of water in open channels, particularly effective for smaller flows. Also known as a triangular weir, its distinctive V-shape allows …

Rectangular weirs and triangular or v-notch weirs are often used in water supply, wastewater and sewage systems. They consist of a sharp edged plate with a rectangular, triangular or v-notch profile …

Mar 28, 2026 · This definitive guide will explore the physics of open-channel flow, detail the specific applications of Rectangular, V-Notch, and Cipolletti weirs, and help you size your environmental …

V-notch weirs are a common method for estimation of discharge flow rate in the field. They comprise a thin plate weir where the area of flow is a notch cut in the shape of a ‘V’ with an internal angle of a …

The Cone equation is commonly used for 90­degree V-notch weirs. This equation is reliable for small, fully contracted weirs generally encountered in measuring water for irrigation.

A v notch weir is simply a ‘v notch’ in a plate that is placed so that it obstructs an open channel flow, causing the water to flow over the v notch. It is used to meter flow of water in the channel, by …

Total flow over trapezoidal weirs with side slopes is computed using the standard weir equation as shown above, plus two times the flow given from the following equation.