The Benefits and Drawbacks of Flow Sensors

The efficiency of a flow heavily relies on various devices used in that particular system. Flow systems vary, and it’s upon their plant manager to decide which equipment is necessary to ensure the productivity is at optimum levels. Among the various devices used are water flow sensors for measuring flow rates of fluids and gases passing through a pipe or a duct. 

Flow sensors are fixed or installed in a flow system to give particular readings based on the preset parameters. An example of a flow meter is used in a motor vehicle’s engine. Its work is to measure the engine’s air intake and provide optimum fuel by adjusting fuel delivery to the fuel injectors. Flow sensors are also used in hospitals to ensure that there is sufficient flow into the patient’s respiratory system.

When using low sensors, ultrasonic detection can be either electronic or mechanical. Flow sensors are further grouped into several categories, including:

  • Multivariable flowmeters 
  • Airflow magnetic flowmeters
  • Thermal flowmeters
  • Positive displacement flow meters
  • Differential pressure flow meters 

 The tight selection of water flow sensors is determined by various factors, including fluid viscosity, the fluid’s properties, the flow rate range, and the accuracy levels required in that particular flow system. The three major flow sensor categories available include velocity flow sensors, positive displacement flow sensors, and mass flow sensors. 

This article will look at the various flow sensors that fall into these three categories, focusing more on their benefits and drawbacks. 

Flow Sensor Types 

Positive Displacement

Of all the flow sensors, positive displacement water flow sensors are the only ones that directly measure the volume of a fluid passing through the flow sensor device. The flow rate in other flow sensors is derived from calculating other parameters such as pressure or density. 


  • Components have high precision with minimum clearances 
  • The level of accuracy and repeatability is very high limited to the amount of slippage 
  • Cost-effective due to low maintenance 
  • Provider reading in both electrical and mechanical interface 
  • Easily designed 
  • Does not need any power 


  • Expensive to install due to moving parts 
  • It can easily rust, especially if used with water-based fluids 
  • They are a bit complex 

Velocity Flow

This type of flow sensor is highly effective for measuring the fluid’s velocity through a sensor. These flow meters come in several varieties: mechanical, ultrasonic, and electromagnetic. In mechanical velocity water flow sensors, moving parts are found where fluid passes, spins, or rotates to measure flow rate. As the fluid flows through the device, it rotates; the paddlewheel and magnetic coil or infrared sensor are used to detect and count the rotations. The output signal is produced when electronics convert rotations from the sensor. 

Mass Flow

Another name for mass flow sensors is mass airflow sensors. These types of flow sensors use the Coriolis working principle. They are largely used in automobiles for measuring the air that goes into the air intake system in internal combustion engines. This is done by measuring the transferred energy to a flowing fluid from the heated surface. There are three ways to do this:

  • By introducing the thermal energy and reading the temperature change 
  • By measuring the amount of energy needed to maintain a consistent temperature 
  • By measuring the current needed to maintain temperature, introducing electric current to a resistive wire  

The two types of mass flow sensors include Coriolis and thermal flow sensors. 


  • Measure fluid flow rate directly with high accuracies 
  • Used to measure highly viscous fluids and several other measurable fluids 
  • Offer bidirectional flow measurement 


  • Not ideal for measuring fluids with low density 
  • Poor zero stability
  • Vibrations can interfere with the readings since they are very sensitive 


Flow rate measurement requires flow sensors to achieve accuracy and productivity. These flow rate reading devices are designed differently to cater to all applications. Always ensure you pair your flow sensors with the right application to get correct and accurate flow rate readings.