Flow Monitoring Unveiled: Is Your Doppler Flowmeter Installed in the Right Position? [Dayu Electronics]

　　The ultrasonic Doppler velocity and flow meter can be used for flow monitoring in various environments, such as rivers, culverts, reservoirs, main irrigation canals, urban inland rivers, urban stormwater and sewage pipe networks, urban trunk sewage pipelines, wastewater treatment plants, industrial wastewater outlets, and mining wastewater outlets. Due to the unique conditions of each measurement site and variations in water level, it is not always possible to follow the standard installation principles during installation. In such cases, a thorough understanding of the installation principles is required to make appropriate adjustments to the installation position based on the specific environment, ensuring the flow meter provides data that is as accurate as possible.

　　First, let's take a look at an on-site installation of a Doppler velocity meter for river flow monitoring: (The customer reported that the measured flow velocity was significantly lower than the actual flow velocity)

　　River Flow Monitoring Point—Doppler Velocity Meter

　　As shown in the figure, the Doppler velocity meter is installed in a small rectangular channel on the right side of the river. Due to the low flow rate at the site and the special shape of the river, the Doppler velocity meter could not be installed at 15% to 20% of the total river width.

　　However, the installation principles for the ultrasonic Doppler velocity meter in similar channels are as follows:

　　1. The flow velocity sensor should be installed at 15% to 20% of the total channel width:

　　2. Install the velocity meter upstream of the weir. Due to the flow-blocking effect of the weir, water below the weir crest may flow slowly, and the velocity distribution by depth is as follows:

　　Since the bottom layer flow velocity is slow, the sensor should be installed 5-10 cm below the weir crest and at a horizontal distance upstream where the flow velocity is stable.

　　Install at a horizontal distance of 30 times the weir height upstream.

　　Therefore, the ideal installation position should be adjusted as shown in the figure:

　　This ensures that the flow velocity measured by the Doppler flowmeter is true and effective.