Flow · Comparison

Vortex vs Magnetic Flow Meter

Side by side comparison: how they work, where each fits, and which to choose.

Quick answer: Vortex meters handle steam, gas and non conductive liquids; magmeters handle conductive liquids and slurries with no pressure loss and down to very low flow.

Vortex vs Magnetic Flow Meter: Comparison Table

Aspect	Vortex	Magnetic Flow Meter
Principle	Counts vortices shed from a bluff body	Voltage induced in conductive liquid
Fluids	Steam, gas, clean liquids	Conductive liquids, slurries
Low flow	Cuts off below a minimum Reynolds number	Measures down to very low velocity
Pressure loss	Moderate	Almost none
Sensitive to	Pipe vibration, swirl	Air in the pipe, empty pipe
Turndown	about 10:1 to 20:1	often 100:1 or more

Choose Vortex when

Saturated and superheated steam
Gas and non conductive liquids

Choose Magnetic Flow Meter when

Water, chemicals and slurries
Wide flow range and low flows

Key Differences Explained

Vortex frequency is proportional to velocity over a wide Reynolds number range, so the meter has a fixed K factor. Below the minimum Reynolds number vortices become unstable and the meter cuts off.

Magmeters need conductivity and a full pipe, but they are unaffected by density, viscosity and moderate solids.

Related Glossary Terms

GlossaryVortex Flow MeterA vortex flow meter counts the vortices shed from a bluff body; their frequency is proportional to…GlossaryElectromagnetic Flow MeterAn electromagnetic flow meter measures the velocity of conductive liquids from the voltage induced…GlossaryReynolds NumberReynolds number is the ratio of inertial to viscous forces in a flowing fluid. It shows whether pipe…GlossaryTurndown RatioTurndown ratio is the maximum flow divided by the minimum flow a meter can measure within its stated…

Free Calculators

CalculatorVortex Flow Meter CalculatorFree online calculator with formula and worked example.CalculatorMagnetic Flow Meter Sizing CalculatorFree online calculator with formula and worked example.CalculatorTurndown Ratio CalculatorFree online calculator with formula and worked example.

Frequently Asked Questions

What is the difference between Vortex and Magnetic Flow Meter?

Vortex meters handle steam, gas and non conductive liquids; magmeters handle conductive liquids and slurries with no pressure loss and down to very low flow.

Can a vortex meter measure water?

Yes, clean water at sufficient velocity.

Why does vortex read zero at low flow?

Below its minimum velocity vortices are weak, so the meter applies a cutoff.

Which is better for steam?

Vortex; magmeters cannot measure steam.

Learn more on the blog

Types of flow meters

A practical guide on instrumentationblog.in that goes deeper into this topic with field examples.

Read Full Article

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