What is a flow meter?

A flow meter is an instrument used to measure the velocity or flow rate of liquids or gases, and is widely used in industrial production, agriculture, and scientific research.

A flow meter is used to measure liquids or gases.flow rateorFlow MeterThese instruments are widely used in industrial production, agriculture, and scientific research.

FlowmeterTypes and working principles

Based on their measurement principles, flow meters can be mainly classified into the following types:

  • Electromagnetic flow meters:
    • principleBased on Faraday's law of electromagnetic induction, the induced electromotive force generated by a conductive liquid cutting a magnetic field is measured.
    • Be applicableSuitable for measurementConductive liquidSuitable for mud, slurry, water, and wastewater. Not suitable for non-conductive media such as gases, oils, or organic solvents.
    • advantageWith no moving parts, minimal pressure loss, and low maintenance requirements.
    • Types such as: FMG electromagnetic flowmeter
  • Ultrasonic Flow Meters:
    • principle: Flow velocity is measured by the propagation time or frequency shift of ultrasonic signals in fluids (Dupler effect).
    • Be applicableSuitable for a variety of liquids, especially suitable forNon-invasive measurementIt can be installed outside the pipe.
    • advantageEasy to install, low maintenance, and versatile.
    • Types such as: UFM ultrasonic flow meters
  • Coriolis Mass Flow Meters:
    • principleIt measures the Coriolis force (torsion or deflection) generated when fluid flows through an oscillating tube, directly measuring the mass flow rate.
    • Be applicableMeasurableAll liquidsAnd gases of medium density.
    • advantage: High precisionIt is unaffected by changes in fluid properties (such as density and viscosity).
    • Types such as: TMFM mass flow meter
  • Turbine Flow Meters:
    • principleWhen fluid flows through the pipe, it drives the internal rotor to rotate, and the rotation speed is proportional to the flow velocity.
    • Be applicableSuitable for clean, low-viscosity liquids and gases.
    • advantageIt is cost-effective and is especially suitable for larger pipe diameters.
    • Types such as: FRV turbine flow meters
  • Thermal Mass Flow Meters:
    • principleMass flow rate is inferred by measuring the difference in thermal conduction between the heating element and the temperature sensor.
    • Be applicableMainly used for measurementgasSuch as compressed air, nitrogen, natural gas, etc.
    • advantageIt directly measures mass flow rate without affecting fluid pressure. 
    • Types such as: TMFC flow meters

How to choose the right flow meter

Choosing the most suitable flow meter requires considering multiple factors:

  • fluid propertiesIs the measured medium a liquid, gas, steam, or slurry? Is it conductive, corrosive, or highly viscous? For example, electromagnetic flowmeters require the fluid to be conductive.
  • Accuracy requirementsHow high a measurement accuracy does the application require? Coriolis flow meters and electromagnetic flow meters typically offer the highest accuracy, while variable area flow meters (rotameters) have relatively lower accuracy.
  • Installation conditionsConsider pipe size, direction (horizontal/vertical), availability of sufficient straight pipe space, and ambient temperature and pressure.
  • Cost and maintenanceBudget constraints and considerations of long-term maintenance costs. Flow meters with no moving parts (such as ultrasonic and electromagnetic flow meters) typically have lower maintenance costs.
  • Data output and integrationDoes it need to be integrated with existing systems? What kind of communication interface and data logging functions are required?

📌 A little reminder

✅ Please consider the following when making your selection:
• Measurement medium(Water/Oil/Steam/Gas)
• Pipe diameter and pressure/temperature range
• Installation mode(Straight-through/Insert/Clamp)
• Interface/communication required?(4-20mA, Modbus, BACnet)

If you tell meMain application (e.g., water pipes/steam pipes/laboratory), pipe diameter and environmentI can help you do a more precise job.Selection RecommendationsWow! 📐

Consulting with a professional supplier or an application engineer from FGT's primary general-purpose manufacturer can help you choose the best solution for your specific challenges.

You are desireUnderstanding the principles,Selection RecommendationsorLooking for commonly used brands in Taiwan/for smart buildingsof?

Let me first give you a simple breakdown to see which type of card you need 👇

Common types of flow meters

If it is a smart building/BMS<—– Understanding Smart Buildings

  • Usually, you would look at:
    • Accuracy (±0.5% or ±1%)
    • Communication (Modbus / BACnet)
    • Are there any agents, verification services, or repair services in Taiwan?
    • Does it comply with the Smart Building Certification and the Ilac-MAR International Certification?

Just tell me in one sentence 👇
👉 Where is it used? (Air conditioning water/tap water/steam)
👉 Is it a new construction project or an existing pipeline?
👉 Do we need to communicate?

I'll directly match it for you.Suitable flow meter type + common Taiwanese brandsfor you.