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When selecting an ultrasonic open-channel flow meter, factors such as the magnitude of the flow in the channel and whether the flow pattern can be that of free flow must be taken into account to choose the appropriate weir. Today, the editor from Jiangsu Evergrande Instruments will introduce to you which type of weir is most suitable for use with ultrasonic open-channel flow meters Firstly, when the flow rate in the channel is less than 40 l/s, a right triangular shape is generally a better choice; when it is greater than 40 l/s, a Parshall groove is preferred. If the flow rate is greater than 40 l/s. At the same time, the water level difference within the channel is relatively large; it is recommended to use a rectangular weir channel, and when conditions permit, a V-shaped channel is the best choice. The relationship between water level and flow rate in the Bachelier channel must be determined through testing; lower requirements are applied to the upstream channel. The relationship between water level and flow rate for triangular weirs and rectangular weirs is derived from theoretical calculations; some practical operating conditions are easily overlooked, which can lead to additional errors. The water measurement flume can be made of fiberglass. The opening dimensions of the triangular and rectangular weirs are quite critical; high precision is required during manufacturing, and the surface on the side facing the water flow must be smooth. For Busschel channels, it is required that the internal dimensions be accurate and the inner surfaces smooth; the throat section is a critical dimension that must be precise! Next, the editor will use images to explain this to you: Image 1: Structure of a right-angled triangular weir; Image 2: Structure of a rectangular weir; Image 3: Structure of a Bézier trough