A velocity-type flow meter would most likely be which technology?

• A. Magnetic
• B. Ultrasonic
• C. Mechanical
• D. Orifice

Answer: (A)

Velocity-type meters determine flow by measuring how fast the water is moving, rather than by weighing a pressure drop. Magnetic flow meters fit this approach because they measure fluid velocity directly: a magnetic field is applied to the conductive water and the voltage generated by its movement is proportional to velocity; knowing the pipe area gives the flow rate. In municipal water systems, water is typically conductive enough for magnetic meters to work well, and these devices have no moving parts and provide reliable, full-bore measurements, making them a common velocity-type choice. Ultrasonic meters can also measure velocity using sound waves, but magnetic meters are the standard velocity-type technology widely used in many distribution setups. The other options rely on different principles—mechanical meters measure rotation to infer volume, and orifice meters rely on differential pressure.