Electromagnetic Flow Meters

Magnetic Flow Meters for Conductive Liquids

Accuracy ±0.5 % of rate
Low-flow detection from 0.3 m/s
Short straight-pipe footprint: 5D upstream, 2D downstream typical

  • Bi-directional measurement, forward and reverse totalizers
  • Multiple liner and electrode material options for medium chemistry
  • Models on the LEA Series
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N COIL S COIL + EMF FLUID IN FLUID OUT Faraday induction across magnetic field Water · Wastewater · Slurry · Acid · Sanitary

The LEA Electromagnetic Flow Meter family measures volumetric flow of conductive liquids by Faraday’s law of electromagnetic induction. A pair of magnetic-field coils generates a stable field across the pipe bore, and two electrodes detect the induced EMF as conductive fluid flows through. The LEA Series delivers ±0.5 % typical measurement accuracy with a 0.3 m/s low-flow detection.

Models cover water and wastewater utility service, slurry and mining process, corrosive acid and chemical liquids, and sanitary food / pharmaceutical applications. Multiple liner and electrode combinations match medium chemistry, and the full-bore design adds zero permanent pressure loss.

LEA-INS insertion models add live-pipe hot-tap retrofit on DN200 to DN3000 mains: a new District Metered Area (DMA) meter, or measurement on legacy cast-iron and cement-lined distribution mains without a shutdown. Lead time is 5–7 business days, factory direct.

Electromagnetic flow meter models

Models on the LEA Series. Click through for spec, configurator, and pricing.

Water Flow Meter

Hard rubber liner standard · 316L electrode · DN10–DN3000

Municipal water supply, distribution mains, industrial process water, and HVAC chilled-water service. The default electromagnetic build for clean conductive water.

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Wastewater Flow Meter

Soft rubber liner · IP68 buried-chamber option

Municipal sewage, industrial effluent, lift-station discharge, and treatment-plant influent / effluent metering with submersible IP68 option.

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Slurry Flow Meter

PU / hard rubber multi-liner · DN6–DN1200

Mining ore slurry, cement raw-meal feed, paper-pulp stock, and sand transport with polyurethane standard (DN6–DN300) or hard rubber alternate (DN300–DN1200) for moderate-abrasion service.

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Corrosive Liquid (Acid) Flow Meter

PTFE / PFA liner · Hastelloy C / Tantalum electrode · DN6–DN600

Strong-acid and oxidising-chemical service on petrochemical, electroplating, and pickle-line applications with chemical-resistant liner and electrode.

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Sanitary Flow Meter

PFA liner · Tri-clamp option · FDA-compliant material

Food, beverage, dairy, brewery, and pharmaceutical process service with PFA liner (FDA-compliant) and Tri-clamp connection option for cleanable / CIP / SIP loops.

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Mining Process Flow Meter

Ceramic + tungsten · DN10–DN300 heavy mining

Tailings, ore concentrate, coal-prep wash, and hydrometallurgical acid-leach service across DN10–DN300 with ceramic (Al₂O₃) liner standard and tungsten carbide / Stellite electrode for sharp-grit service.

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Insertion Electromagnetic Flow Meter

LEA-INS hot-tap probe · DN100–DN3000 · ±1.0 % of rate

Live-pipe retrofit through a ball-valve insert under process pressure. 304 housing with PTFE-lined 316L electrode, calibrated single-point velocity by Nikuradse correction, no shutdown required for large-diameter and legacy-host-pipe metering.

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Hot-Tap Water Flow Meter

LEA-INS water-utility build · DN200–DN3000 · IP65+IP68 split

Municipal water-main retrofit for DMA addition, trunk-main consumption, and legacy cast-iron / cement-lined / HDPE distribution measurement. Ball-valve insert installs under live pressure without service interruption.

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How electromagnetic flow meters work

The LEA Electromagnetic Flow Meter applies Faraday’s law of electromagnetic induction. A pair of magnetic-field coils generates a stable field across the pipe bore. As conductive fluid (≥ 5 µS/cm conductivity) flows through, two electrodes mounted in the pipe wall detect the induced electromotive force across the bore.

The induced EMF is proportional to the average flow velocity across the bore, independent of fluid density, viscosity, temperature, and pressure within the design range.

The full bore is wetted: no obstruction, no bluff body, zero pressure loss. Because the LEA reads the cross-sectional average, it needs only a short 5D / 2D straight-pipe run, far less than vortex or orifice meters.

When to specify electromagnetic

Choose electromagnetic for conductive liquid service where the medium has at least 5 µS/cm conductivity. For non-conductive liquids, dry gas, or steam, see the alternative meter types.

ServiceElectromagnetic (LEA); pick whenAlternative meter type
Water and wastewater utilityStandard pick; full-bore, zero pressure loss, IP68 option
Slurry, ore concentrate, tailingsPolyurethane liner, no obstruction to clogCoriolis tubes clog on coarse particulate
Strong acid, chloride chemistryPTFE / PFA liner, Tantalum or Hastelloy C electrodeVortex bluff body corrodes
Sanitary food / pharmaPFA liner, Tri-clamp connection optionVortex bluff body fouls CIP
Tight retrofit, < 10D upstream pipeShort 5D/2D straight-pipe footprint; key advantageVortex needs 10D / 5D, swirl 3D / 2D
Bi-directional flow (return mains)EMF polarity reverses with direction, dual totalizer standardVortex / orifice direction-aware add-on
Non-conductive liquid (thermal oil, glycol, hydrocarbon)Below 5 µS/cm conductivity floorVortex (LUGB) liquid build
Steam, dry gas, low-density gasEMF only measures conductive liquidVortex / Swirl / Thermal Mass families
Custody transfer fiscal primaryApproved on water utility, not on hydrocarbonsCoriolis (ZLMFM) or AGA 9 ultrasonic

Liner & electrode selection by chemistry

Match the wetted-parts combination to the medium chemistry. The choice drives both model selection and lifecycle cost.

Service chemistryLinerElectrodeModel page
Clean water (municipal, HVAC, process)Hard rubber (D)316LWater Flow Meter
Municipal sewage, lift-station dischargeSoft rubber (E)316LWastewater Flow Meter
Mining ore slurry (DN6–DN300)Polyurethane (F)316L or tungstenSlurry Flow Meter
Mining slurry larger DN (DN300–DN1200)Hard rubber (D)316L or tungstenSlurry Flow Meter
Heavy mining (tailings, ore concentrate > 30 % solids)Ceramic (Al₂O₃)Tungsten / StelliteMining Process Flow Meter
Strong acid (HCl, H₂SO₄, HNO₃ general)PTFE (C)Hastelloy CCorrosive Liquid Flow Meter
Hot strong acid (hot HCl, hot conc. H₂SO₄ above 80 °C)PTFE (C)TantalumCorrosive Liquid Flow Meter
High-purity chemical service (electronic / fine chemical)PFA (p)Hastelloy C / TantalumCorrosive Liquid Flow Meter
Food, dairy, brewery, pharmaceutical (CIP / SIP)PFA (p)316LSanitary Flow Meter
Hydrometallurgical acid-leach (Cu, Zn, Ni, Au)Ceramic + PTFE optionStelliteMining Process Flow Meter

PFA is FDA-compliant. Send chemistry by name and concentration / temperature window at quote stage; the engineering team confirms the matched liner-electrode pair within 4 business hours.

Model specification comparison

Side-by-side spec across the eight LEA models; six inline models and two LEA-INS hot-tap insertion models.

ModelDN rangeLiner standardElectrode standardMedium tempTypical service
WaterDN10–DN3000Hard rubber316L0 to +80 °CMunicipal & industrial water utility default
WastewaterDN10–DN3000Soft rubber316L0 to +80 °CSewage + lift-station + WWTP, IP68 buried option
SlurryDN6–DN1200PU + hard rubber316L / Tungsten−10 to +80 °CGeneral industrial slurry, multi-liner build
Corrosive LiquidDN6–DN600PTFE + PFAHastelloy C / Tantalum−25 to +180 °CStrong acid + oxidising chemical
SanitaryDN6–DN200PFA316L0 to +180 °C (SIP +135 °C)Food / dairy / brewery / pharma, Tri-clamp option
Mining ProcessDN10–DN300Ceramic + PU alternateTungsten / Stellite−10 to +120 °CHeavy mining: tailings, ore concentrate, acid leach
Insertion EMFDN100–DN3000PTFE-lined 316L probe316L (probe-integrated)≤ 70 °C one-piece / ≤ 120 °C splitHot-tap retrofit, large-DN, legacy host pipe
Hot-Tap WaterDN200–DN3000PTFE-lined 316L probe316L (probe-integrated)0 to +70 °C municipal waterDMA addition, trunk-main, cast-iron retrofit

All eight models share the LEA Series: Faraday induction, ≥ 5 µS/cm conductivity threshold, multiple liner and electrode options, 4-20 mA + RS485 + pulse + 4G IoT outputs, EMC 2014/30/EU compliance, 5–7 business days lead time. Inline models achieve ±0.5 % of rate across 0.3 to 15 m/s; LEA-INS insertion models achieve ±1.0 % of rate calibrated 0.5 to 10 m/s via Nikuradse single-point velocity correction.

Universal install requirements

The LEA Series shares one install baseline across its six inline models. Model-specific variations live on each model page; this baseline applies to every inline electromagnetic flow meter. LEA-INS insertion models follow a separate hot-tap procedure documented on each insertion model page.

  1. Vertical mounting preferred, electrodes 3 and 9 o’clock if horizontalVertical bottom-to-top guarantees full-bore wetting (mandatory for liquid-solid two-phase service). Horizontal install only with electrodes on the same horizontal plane.
  2. Install valves and bypass loop at both ends of sensorAllows sensor isolation for inspection, cleaning, or replacement without shutting down the process line.
  3. Ground sensor + pipe + converter to ≤10 Ω, separate from other equipment groundThe few-millivolt EMF references internal sensor potential. On non-metallic pipe (HDPE, GRP, PTFE-lined), install metallic grounding rings between meter and pipe flanges.
  4. Use shielded signal cable ≤30 m, never parallel with power in same conduitSensor-to-converter signal must use the supplied shielded cable (max 30 m standard). Maintain 300 mm separation from VFD and motor-drive cables.
  5. Do NOT install on the pump suction side; place regulating valves downstreamVacuum-induced negative pressure breaks the EMF measurement. Always install on pump discharge; place regulating valves downstream of sensor (never upstream).
  6. Straight-pipe ≥10D upstream / ≥5D downstream for larger DN; 5D/3D minimum in harsh conditionsSmall-bore meters do not require upstream straight pipe (electrode-to-inlet distance equals several diameters). Larger DN meters need ≥10D / ≥5D; harsh-environment minimum is ≥5D / ≥3D.

Model-specific install rules (IP68 buried for wastewater, vertical mandatory for slurry, grounding rings for chemical PTFE/PFA, Tri-clamp specifics for sanitary, electrode wear monitoring for heavy mining) live on each model page. The six rules above are the universal baseline.

Frequently asked questions

What is an electromagnetic flow meter and how does it measure flow?+
An electromagnetic flow meter measures volumetric flow of conductive liquid by Faraday’s law of electromagnetic induction. A pair of magnetic-field coils generates a stable field across the pipe bore. As conductive fluid flows through the field, an electromotive force is induced across two electrodes in the pipe wall, with magnitude directly proportional to the average flow velocity. The LEA Series delivers ±0.5 % typical measurement accuracy.
What is the conductivity threshold for electromagnetic measurement?+
Electromagnetic flow meters require a minimum fluid conductivity for the induced EMF to exceed sensor noise. Industry-standard threshold is 5 µS/cm; well below tap water (50–500 µS/cm), seawater (50,000 µS/cm), and process water with any dissolved salts. Demineralised water, condensate, and pure organic solvents are below threshold; for those, choose vortex, Coriolis, or thermal mass.
What straight-pipe footprint does an electromagnetic flow meter need?+
The LEA measures average velocity across the full pipe cross-section via induced EMF, not single-point or vortex shedding. Velocity-profile asymmetry has less effect on the cross-sectional average than on point meters, so the requirement is short: 5D upstream and 2D downstream. Half the vortex 10D/5D rule and a quarter of orifice 20D/5D, which is why LEA fits retrofit skids where vortex and orifice cannot.
What liner and electrode materials are available?+
Multiple liner and electrode options match medium chemistry. Liners: PTFE (chemical), PFA (high-temp pharma), polyurethane (abrasive slurry), rubber (water / wastewater). Electrodes: 316L (water / weak acid), Hastelloy C-276 (chloride / oxidising), Titanium (seawater), Tantalum (strong acid). Specific tables confirmed at quote.
When should I choose electromagnetic instead of vortex, ultrasonic, or Coriolis?+
Choose electromagnetic for conductive liquid (≥5 µS/cm) on DN10+ full-bore wetted lines. Full-bore zero-pressure-loss and 0.3 m/s low-flow detection are key advantages on water, wastewater, slurry, sanitary, and corrosive chemical service. Choose vortex for steam, dry gas, and non-conductive liquid. Choose Coriolis for custody or high-viscosity. Choose ultrasonic for non-invasive clamp-on retrofit.
Can the meter measure flow in both directions?+
Yes; bi-directional measurement is a standard LEA feature. The polarity of the induced EMF reverses with flow direction, and the on-board converter outputs forward and reverse flow with direction indication and separate totalizers. Bi-directional service is standard for water-distribution mains with potential reverse flow, district-heating return lines, and wastewater lift-station discharge.
What is the lead time and what certification ships standard?+
Standard lead time is 5–7 business days from order confirmation, factory direct. The LEA Series ships with EMC compliance to the EU Electromagnetic Compatibility Directive 2014/30/EU (Annex II) and IP65, IP66, or IP67 ingress protection (selectable). IP68 submersible option is available for buried installations and lift-station service.

Need help selecting an electromagnetic flow meter?

Send the line size, design pressure, medium (water, wastewater, slurry, acid, sanitary), and conductivity. The engineering team returns a sized model code, an estimated unit price, and a ship window within one business day. Lead time stays 5–7 business days from the factory.