Flow Meter

Electromagnetic Flowmeter

The working principle of an electromagnetic flowmeter is based on Faraday’s law of electromagnetic induction. The measuring tube is made of a non-magnetic alloy and internally lined with an insulating material to prevent signal interference and ensure measurement stability.

Two measuring electrodes are installed diametrically opposite on the inner wall of the flow tube, with the electrode surfaces flush with the lining. When the excitation coils generate a pulsed magnetic field perpendicular to the flow direction, a uniform magnetic flux density is formed across the measuring section.

As a conductive liquid flows through the magnetic field inside the tube, it cuts the magnetic lines of force and generates an induced electromotive force. This induced voltage is proportional to the magnetic flux density, the inner diameter of the pipe, and the average velocity of the fluid. The electrodes detect this voltage signal and transmit it to the converter through shielded cables.

The converter amplifies and processes the signal, converting it into a flow rate value. The electromagnetic flowmeter then outputs standard signals such as pulse output and analog current (4–20 mA), enabling real-time flow display, process monitoring, flow control, and system integration in industrial automation applications.

  Flow Meter Description  

Electromagnetic Flowmeter-Features

  • The electromagnetic flowmeter delivers stable electromagnetic flow measurement that is independent of fluid density, viscosity, temperature, pressure, and conductivity, reducing recalibration frequency and long-term operating costs.

  • With a full-bore design and no moving parts, the electromagnetic flow meter eliminates pressure loss and minimizes maintenance, making it ideal for continuous operation in slurry, wastewater, and corrosive liquid applications.

  • A wide DN6–DN3000 size range, combined with multiple lining and electrode material options, allows one electromagnetic flowmeter platform to cover diverse processes, reducing spare parts inventory and total cost of ownership.

  • Advanced low-frequency rectangular wave excitation and full digital signal processing ensure high measurement stability and strong anti-interference performance, even in electrically noisy industrial environments.

  • The 32-bit embedded processor enables fast signal calculation and a wide measurement range of up to 1500:1, allowing accurate flow monitoring under both low-flow and peak-load conditions without changing instruments.

  • Integrated diagnostics, empty pipe detection, and conductivity monitoring improve operational safety and reduce unexpected downtime, supporting predictive maintenance strategies.

  • Multiple industrial communication protocols, including RS485, HART, and optional Profibus, ensure seamless system integration and protect automation investments over the long term.

  • Explosion-proof options and robust SMT-based electronics provide reliable performance in hazardous and harsh environments, extending service life and maximizing return on investment.

Electromagnetic flowmeter structure diagram showing measuring tube, electrodes, coils, and liner components.
Electromagnetic flow meter installed on a pipeline with flanged connections and a digital transmitter for online measurement of conductive liquid flow.

Electromagnetic Flow Meter-Applications

Water & Wastewater
Electromagnetic flowmeters are used for raw water intake, distribution pipelines, effluent discharge, and sludge measurement, providing stable electromagnetic flow measurement for municipal and industrial water systems.

Chemical & Pharmaceutical
Electromagnetic flowmeters measure corrosive chemicals, acids, alkalis, and process liquids with high accuracy, supported by multiple lining and electrode options for chemical compatibility.

Food & Beverage
Sanitary electromagnetic flow meters are applied to beverages, dairy products, syrups, and process water, supporting hygienic electromagnetic flow measurement and batch consistency.

Pulp & Paper
Electromagnetic flowmeters are suitable for stock preparation, white water circulation, chemical dosing, and wastewater monitoring in fiber-rich process environments.

Power & Cooling Water
Electromagnetic flowmeters monitor cooling water circulation and auxiliary water systems, helping improve system efficiency and operational reliability.

Mining & Slurry
Electromagnetic flowmeters are ideal for abrasive slurry, tailings, and mineral processing fluids, delivering reliable electromagnetic flow measurement in harsh industrial conditions.

Electromagnetic Flowmeters-Measuring Principle

The measuring principle of an electromagnetic flowmeter is based on Faraday’s law of electromagnetic induction. The measuring tube is a non-magnetic alloy spool lined with an insulating material to ensure stable electromagnetic flow measurement and eliminate signal interference.

Two electrodes are mounted diametrically through the pipe wall and fixed on the measuring tube, with the electrode surfaces flush with the inner lining. When the excitation coils are driven by a bidirectional pulsed current, a working magnetic field with a magnetic flux density B is generated in a direction perpendicular to the pipe axis.

As a conductive fluid flows through the measuring tube of the electromagnetic flow meter, it cuts the magnetic field lines and an induced electromotive force E is generated. The induced voltage is directly proportional to the magnetic flux density B, the inner diameter of the measuring tube d, and the average flow velocity v of the fluid.

The electromotive force E, which represents the electromagnetic flow measurement signal, is detected by the electrodes and transmitted to the converter via shielded cables. The converter amplifies and processes the signal, calculates the flow rate, and displays the measurement result. Standard output signals such as pulse output and analog current (4–20 mA) are provided for flow monitoring, control, and process regulation in industrial automation systems.

Electromagnetic flowmeter working principle diagram showing conductive liquid flowing through a magnetic field and generating voltage signals at electrodes.
Electromagnetic flowmeter structure diagram showing all-in-one and split type designs, including installation structure, flange dimensions, and display unit layout.

Flowmeter Electromagnetic-Structure

Selection ItemIntegral Electromagnetic FlowmeterRemote Electromagnetic Flowmeter
StructureSensor and converter integrated into one unitSensor and converter installed separately
Typical ApplicationStandard industrial environmentsHarsh or complex installation environments
Ambient TemperatureSuitable for moderate temperaturesRecommended when ambient or radiant temperature exceeds 60°C
Pipeline VibrationSuitable for low-vibration pipelinesBetter for strong or continuous vibration conditions
Corrosive EnvironmentLimited resistance if exposed to corrosive gasesConverter can be installed in a safe, non-corrosive area
Installation AccessibilityEasy local operation and commissioningIdeal for high or hard-to-access installation points
Maintenance & OperationSimple wiring, quick installationEasier maintenance with remote access to the converter
Installation FlexibilityCompact, space-saving designHigh flexibility for sensor and converter placement
Cable Length RequirementNo separation cable requiredSensor–converter distance up to 100 m (to be specified when ordering)
Converter MountingIntegrated on the sensorWall-mounted converter as standard
Recommended UsersCost-sensitive projects with standard conditionsProjects prioritizing reliability, safety, and long-term stability

  Flow Meter Parameter  

PTFE Lined Pipe(Dn)10, 15, 20, 25, 32, 40, 50, 65, 80, 100, 125, 150, 200, 250, 300, 350, 400, 450, 500, 600
Rubber Lined Pipe(Dn)40, 50, 65, 80, 100, 125, 150, 200, 300, 350, 400, 500, 600, 800, 1000, 1200, note: special specifications can be customized
Measuring Range Ratio150:01:00
Repeatability Error+/-0.1%
AccuracyPiped: 0.5 class, 1.0 class
Measured Medium TemperatureCommon rubber lining: -20~+60 ° c
High temperature rubber lining: -20~+90 ° c
PTFE lining: -30~+100 ° c
High temperature vinyl lining: -30~+180 ° c
Rated working pressurePipeline: DN10~DN65: ≤ 2.5MPa;DN80~DN150: ≤ 1.6MPa;
DN200~DN1200: ≤ 1.0MPa
Flow Measuring RangeFlow measuring range corresponding to flow rate range is 0.3~15m/s
Measured Fluid Conductivity5μs/cm (Most with water as the composition of the medium, its conductivity in the range 200~800 Mu s/cm, optional solenoid flow)
OutputCurrent:4~20mADC (isolation), pulse frequency 0~1kHz, OCT photoelectric isolation, external power ≤ 35VDC, breakover, collector Max 25mA
Electrode Material316L, titanium (Ti), tantalum (Ta), Hastelloy, (h), Platinum (Pt) or other special electrode materials

  Flow Meter OEM/ODM

Electromagnetic Flowmeter – OEM / ODM

As a professional electromagnetic flowmeter manufacturer, we provide comprehensive OEM and ODM services to support customized electromagnetic flow measurement solutions for global industrial applications.

Our OEM electromagnetic flowmeter service allows customers to apply their own brand identity, including logo, nameplate, housing color, and packaging, while maintaining stable performance and consistent quality standards. This is ideal for distributors, system integrators, and automation solution providers.

Through ODM customization, we support full product development based on specific application requirements. Customization options include nominal diameter, flow range, lining materials, electrode materials, pressure rating, power supply, and communication protocols such as 4–20 mA, HART, Modbus, and Profibus. Explosion-proof and high-protection designs are also available for demanding environments.

Each customized electromagnetic flow meter is engineered, assembled, and tested in-house to ensure measurement accuracy, long-term stability, and compatibility with the target process conditions. This OEM / ODM capability enables customers to reduce development time, control total cost of ownership, and accelerate market entry.

Industrial instrument manufacturer production workshop showing large-scale manufacturing of level gauges and process instruments

  Related Product Recommendations  

An electromagnetic flowmeter is designed for electromagnetic flow measurement of conductive liquids only. Typical measurable media include water, wastewater, acids, alkalis, slurry, pulp, chemicals, and process liquids.
The minimum conductivity requirement is usually ≥5 μS/cm (some models ≥1 μS/cm with special excitation).

Liquid TypeSuitabilityNotes
Clean waterExcellentMost common application
WastewaterExcellentNot affected by impurities
SlurryExcellentNo moving parts, no blockage
Oil / GasNot suitableNon-conductive
Deionized waterLimitedConductivity must be verified

This makes the electromagnetic flow meter especially suitable for water treatment, chemical processing, and slurry transport.

standard industrial electromagnetic flowmeter typically offers an accuracy of ±0.5% of reading, with high-end models reaching ±0.3%. Accuracy remains stable because electromagnetic flow measurement is independent of fluid density, viscosity, pressure, and temperature.

Flowmeter TypeTypical AccuracyMoving Parts
Electromagnetic flowmeter±0.3% – ±0.5%No
Turbine flowmeter±0.5% – ±1.0%Yes
Ultrasonic flowmeter±0.5% – ±1.0%No
Orifice plate±1.0% – ±2.0%No

For long-term ROI and low maintenance, electromagnetic flow meters are often preferred in continuous industrial processes.

Electromagnetic flowmeters support a very wide nominal diameter range, typically from DN6 to DN3000, making them suitable for both small dosing lines and large pipelines.

ParameterRange
Nominal diameterDN6 – DN3000
Flow velocity0.1 – 10 m/s
Measurement range ratioUp to 1500:1

This wide range allows one electromagnetic flowmeter platform to cover multiple applications, reducing spare parts inventory and system complexity.

The performance and service life of an electromagnetic flowmeter depend heavily on correct material selection. Different media require different lining and electrode combinations to ensure corrosion resistance and signal stability.

MediumLining MaterialElectrode Material
Water / wastewaterRubber / PTFESS316L
Acid / alkaliPTFE / PFAHastelloy
SlurryRubber / CeramicSS316L / Hastelloy
High corrosionPTFETantalum

Proper material selection improves measurement reliability and significantly reduces total cost of ownership.

Modern electromagnetic flowmeters support multiple analog and digital outputs for seamless integration into automation systems.

Output TypePurpose
4–20 mAProcess control
PulseFlow totalization
RS485 / ModbusPLC and SCADA
HARTConfiguration and diagnostics
ProfibusIndustrial networks (optional)

These communication options ensure the electromagnetic flow meter remains compatible with current and future control systems.

As an OEM / ODM manufacturer, we provide deep customization for electromagnetic flowmeters to match specific project requirements and branding needs.

Customization ItemOEMODM
Logo & nameplateYesYes
Housing colorYesYes
Diameter & pressureLimitedFully customizable
Lining & electrodeStandard optionsApplication-specific
Communication protocolOptionalFully selectable
Explosion-proof designOptionalCustom certified

OEM electromagnetic flowmeter solutions help customers shorten delivery time, while ODM solutions support differentiated products and faster market entry.

Why Choose Instrava

By choosing Instrava, you gain a partner with a deep understanding of industrial applications and the expertise to meet today’s operational challenges.
Our role extends beyond products—we support your success through dependable solutions and long-term commitment.

Engineering-Driven Innovation

Innovation at Instrava is guided by real industrial requirements. We continuously refine our technologies to address evolving operational challenges, ensuring practical and reliable performance in demanding environments.

Application-Specific Customization

We provide engineering-level customization to match specific process conditions. From measurement range and materials to output signals and installation options, our solutions are configured to fit real applications.

Proven Quality and Reliability

Quality and reliability are fundamental to every Instrava product. Manufactured under strict quality control and thoroughly tested, our instruments deliver accurate, stable, and long-term performance.

Global Capability with Local Support

Instrava combines global engineering expertise with responsive local support, ensuring our partners benefit from internationally aligned technology and timely regional service.

Comprehensive Product Portfolio

Our broad portfolio of measurement and control instruments enables us to address a wide range of industrial needs, providing integrated solutions from a single, reliable source.

Partner-Oriented Engineering Support

We work closely with our partners from technical consultation to after-sales support. Our focus is on delivering solutions that create lasting value and support long-term operational success.