Description: Compared with traditional water flow meters, Doppler flow meters use an integrated packaging structure, which is waterproof, pressure-resistant, and wear-free. The closed structure is not affected by the external environment and has a low failure rate. At the same time, it has little effect on the water flow state, is not affected by impurities and other debris in the water flow, and will not fail to work due to blockage. Using the Doppler frequency shift principle, the detection accuracy reache