ity when the ultrasonic beam propagates downstream and countercurrent in water, and then calculates the flow rate of water by analyzing and processing the flow rate of water.?TYPES BY THE PRINCIPLE OF MEASUREMENTVelocity water meter and volumetric water meterVelocity water meter: A water meter installed in a closed pipe consisting of a moving element which is directly caused by the moving velocity of the water flow to obtain the dynamic velocity. Typical velocity water meter has vane wheel and