How Does a Doppler Ultrasonic Flowmeter Measure Natural River Flow? [Dayu Electronics]
Doppler ultrasonic flowmeter is a flow measurement instrument based on the acoustic Doppler effect principle. It uses ultrasonic transducers to detect flow velocity with ultrasound. The measurement point is in front of the probe, without disturbing the flow field. It offers high measurement accuracy, wide range, the ability to measure both weak and strong currents, high resolution, fast response, and can measure instantaneous or average flow velocity. The measurement is linear, and the velocity calibration curve is stable. It has no mechanical rotating parts, avoiding issues with sediment blockage and weed entanglement. The probe is rugged and durable, not easily damaged, and easy to operate.
Key installation points when using a Doppler flowmeter to measure natural river flow:
1. Wrap the flow sensor with rubber sheet at least 2 mm thick and connect it to the mounting base with a clamp. An inner tube from a car tire can also be used. The mounting base connects to the "river bottom fixing bracket".
2. The flow sensor should be placed in a stable water flow area. There must be no obstacles within 2 meters directly in front of the sensor, and no obstacles within 1 meter on either side.
3. There must be at least 20 cm of water above the top of the flow sensor.
4. Avoid dead water zones at the installation site.
5. The pole for installing the "wireless transmission equipment and instrument box" should be made of galvanized steel pipe, with a diameter of DN100, wall thickness of 5 mm, and a total height of 4 meters.
6. The installation pole should be buried in a location that is not submerged by floodwater during the flood season.
7. The installation pole will have solar panels, batteries, a solar controller, an instrument box, a low-power GPRS wireless data transmission and acquisition card, and a lightning rod.
8. A lightning protection grid should be laid at the base of the installation pole, and the lightning rod on the pole should be connected to the grid with copper wire.