Water measuring equipment can be divided into pipes and open channels according to flow conditions. Commonly used water equipments for pipes include water pipe injection method, round neck meter method and pipe measurement method (flowmeter, commonly known as water meter). ), in which the tube and instrument sensing method can be divided into ultrasonic, electromagnetic, differential pressure, propeller, vortex and volumetric, etc. The same types. Because the section of the pipe is relatively fixed (the premise is a full pipe), its measurement operation mainly measures the velocity in the pipe, which can be integrated with the water flow area to obtain the flux. Open channel water refers to the source of raw water being transported in open channels. Various open channels and water facilities must measure the water level sufficient to calculate the area of ​​the water passing through and the amount of water passing through. The water used for the accumulation is generally used to measure the water level. The methods are: (1) staff gauge or hook gauge (point or hook gauges), (2) ultrasonic gauges, (3) pressure transducer, (4) float type Water level gauge (float operated gauges), (5) (radar gauges), etc. For fixed-section channels, after taking the water level or depth, use the water level-flux (HQ) or water level-area-volume (HAV) relationship to convert to flux or water. Calculate the water passed during the measurement period for the fixed condition accumulation.

                                              Figure: Schematic diagram of the relationship between water sources and water intake facilities and water measuring equipment
References: 2016 Water Measuring Equipment Administrative Management and Counseling Improvement Plan and Water Resources Agency e-newsletter Issue 0131