A water flow meter is a measuring device specifically used to measure the amount or volume of water passing through pipes. If you are looking for a water flow meter for an industrial application, you can choose from different technologies which suit varying budget allocations, measurement requirements, and maintenance complexity. According to the working principle of each type of water flow meter, you can better determine which type best suits the intended application. Here are the four types of water flow meters used today.
Mechanical water flow meters:
A mechanical flow meter is the simplest, cheapest, and easiest to operate. These devices consist of a paddlewheel, propeller, and turbine. The turbine which rotates around the flow meter measures the speed of water flowing through the pipe. By measuring the speed of rotation, you can also get the corresponding volume of flow rate because it is directly proportional to the speed. While mechanical flow meters are simple to use, they are prone to clogging and will not work efficiently when water has large particles and other contaminants. These are also not suitable for measuring water flow rate when the pressure is too low.
Ultrasonic water flow meter:
An ultrasonic flow meter uses ultrasound in measuring fluid flow speed which then corresponds to the volume of flow. The working principle of a basic ultrasonic flow meter is that the device transmits a signal in the same direction as the fluid flowing downstream, and another ultrasonic signal is emitted against the upstream fluid flow. The amount of time it takes for the signal to travel downstream is compared with the amount of time it takes for the signal to travel upstream. The difference produced will be used in calculating the fluid velocity.
Magnetic water flow meter:
In contrast with ultrasonic flow meters using ultrasound signals, a magnetic water flow meter uses a magnetic field for measurement. When any liquid passes through a magnetic field, it will generate a voltage. The faster the fluid moves, the more voltage is produced. As such, the amount of voltage is directly proportional to the water’s movement and speed. There are corresponding electrical parts which translate the voltage into a volumetric measurement. One limitation of a magnetic flow meter is that it only has intermediate accuracy. Aside from this, it cannot measure pure water due to lack of ions which will not produce the necessary magnetic field reaction.
Vortex water flow meter:
The working principle of this type of flow meter uses vortices coming from a sensor submerged in the fluid. As water passes through this sensor or obstruction, it creates swirls, and the sensor will move from side to side with each passing vortex. This continuous movement creates a frequency which is also directly proportional to the flow rate volume. There are vortex flow meters which can measure multiple variables such as density, pressure, mass flow, temperature, and flow rate.
While all these flow meters are suitable for measuring water flow, choosing a flow meter still depends on the desired application because each type will still have limitations and some work best in certain conditions.