Flow meters work by measuring the amount of gas, liquid, or steam that passes through or around their sensors. This article will explain the differences between the various flow meter types and help you choose the ones that will deliver accurate and repeatable measurements for specific applications, whether for general research, process control, or monitoring.

To know more about ultrasonic flow meters, you can read the Visaya Article here

What is a flow meter?

Flow meters measure either mass or volume. In a volumetric flow meter, the flow (Q) equals the cross section of the pipe (A) times the velocity of the fluid (v):  Q = A * v

And for things like chemical reactions, combustion, or buying and selling gases, we need the mass flow rate. So in a mass flow meter, the mass flow (ṁ) equals the volumetric flow rate (Q) times the fluid density (ρ): ṁ = Q ∗ ρ

Flow Meter Types

Magnetic Flow meter: Here, the measured liquid must be water based or conductive. This makes the mag meter a great choice for waste water or process water that is considered fouled or dirty.

Picomag electromagnetic flow meter from Endress + Hauser Smart electromagnetic flowmeter with wireless remote access
in the shop from 432 €

Capillary thermal mass flow meter: Here, there is a thermal heat transferring between gas in a very small tube (the capillary) and a set of sensors indicates the gas mass flow.

Immersible thermal mass: Here, there is more thermal heat, but there is a difference: the thermal heat is transferred from a heated sensor immersed in the flow.

Vortex shedding flow meter: This is another sensor immersed in the flow, but this  uses vortices and a computed fluid density so as to measure volumetric and/or mass flow.

Transit-time ultrasonic flow meter: This flow meter can sense flow speed from outside the pipe with an ultrasound. As such, it is not necessary to immerse. 


To know more about water flow meters, you can read the Visaya Article here

Applications for various flow meter types

There are a number of applications where a flow meter can work. Some of them include catering to gas, liquid or steam; very large flows or only small flows; high or low temperature or pressure conditions; simple or complicated pipe layouts or costly products that need precise measurement. Also, some flow meters work better when measuring different things.

GF Piping Systems
Ultraflow U1000 Ultrasonic clamp-on flow sensor with display
in the shop from 1916 €

Here are the few cases where flow meters can be used:

  • Thermal mass flow meters: These flow meters can precisely measure mass flow of gases from low to high flows.
  • Vortex meters: These flow meters are ideal for measuring liquid and steam flows at high temperatures and pressures.
  • Ultrasonic meters: These flow meters work well in liquids when we want to avoid pipe cutting or shutdown

    To know more about such products, you can
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