Home Technology Water flow Sensors: Types and Advantages

Water flow Sensors: Types and Advantages

water flow sensors- Water flow Sensors: Types and Advantages

Water flow sensors are tools that help you to gauge the speed of water or water-like liquids within a flow channel. Different flow sensors depend on the needs of a firm. Each type has some advantages over others. As a user, you select the water flow sensor that suits your needs. Below are the typical water flow sensors and their benefits.

Positive Displacement Flow Sensors

These flow sensors do the direct measurement of fluids. They hold a known amount of liquid and release it when the cup or gear is filled. The rotation or oscillations of the flow sensor depends on the speed of the water flow.
These sensors are the only type that will gauge the flow rate directly. Others will measure other water parameters and translate the readings to flow rate measurements. You read the PD measurement in volume per unit time. In most cases, you count the rotation per minute or second.

These water flow sensors apply to a wide range of fluids. It is not limited to pressure or viscosity. There are also a variety of materials to cater to extreme temperature fluids.


  • High accuracy and repeatability
  • Cost-effective since it’s low maintenance
  • Does not use power
  • Can work under high pressures
  • You can use it with dirty and slurry water
  • High precision components with minimal clearance

Velocity Flow Sensors

These flow sensors will give you the flow rate by assessing water velocity against the cross-section area. They are classed into three categories as below.


These are the velocity flow sensors with a moving part within the meter. The rotating device is located within the flow path. As the water passes, the rotating part is moved. What’s different with the PD meter is that it doesn’t hold a known amount of water before releasing downstream.

The sensor has an infrared or a magnetic coil to detest the rotations. Then it sends the signals to the output and displays them on a screen.


  • You can use them with a wide range of fluids
  • They are compact
  • Mechanical water flow sensors are easy to use
  • You get a true mass measurement
  • The sensors give high accuracy
  • Temperature, pressure, and viscosity do not affect the sensors


These meters operate on Faraday’s law of induction. Thus, it is useful when you gauge the flow rate of water with electric properties. As the water passes through the magnetic field, it creates a voltage. The voltage increases with the increase in the water’s flow rate.


  • They have a reliable accuracy
  • They are useful in a wide range of industries
  • You can use them in water with some contamination
  • The fluid only needs to have minimum conductivity to work well with electromagnetic water flow sensors.


These are flow sensors that use transducers to generate a sound signal. The signals are sent upstream and downstream. Since the signal is sent simultaneously and speeds, you gauge the flow rate by the different speeds it moves upstream and downstream.


  • They are durable since they have no moving parts
  • They require minimal maintenance
  • You can choose between the digital and analog options
  • They have high accuracy

Mass Flow Sensors

A mass water flow sensor will gauge the mass flow of water per unit time. They use the Coriolis principle of thermal mass principle. They measure the fluid flow by the rate they transfer heat from one point to another. You need to introduce heat energy at one node and gauge the heat transfer downstream.


  • They gauge fluid flow with high accuracy
  • They give flow gauging for both directions
  • You can use them in a wide range of fluids.
  • They are not sensitive to viscosity, heat, and pressure.


You can use a water flow sensor with an alarm system. It can alert you when the flow rate has dropped below the required speed. It can also use in small industries for accurate measurement.