Control & Instrumentation

Flow Meter Selection Guide: Magnetic, Vortex, Coriolis or Orifice?

A comparison of accuracy, turndown, pressure loss and cost of common technologies, and a three-step selection method.

1 min readUpdated: October 22, 2026
Flow Meter Selection Guide: Magnetic, Vortex, Coriolis or Orifice?

Photo: Vsatinet · CC BY-SA 4.0 · Image credits

Three questions before any selection

  1. What is the fluid? Conductive liquid, non-conductive liquid, gas, steam or two-phase?
  2. What accuracy is needed? Process control, allocation, or custody transfer?
  3. What are the process conditions? Pressure, temperature, viscosity, solids and available straight run.

Technology comparison

TechnologySuitable fluidPressure lossMoving partsNote
OrificeLiquid, gas, steamMedium–highNoneLow cost; needs DP transmitter
MagneticConductive liquidNoneNoneWater, wastewater, slurry
VortexSteam, gas, liquidLow–mediumNoneSteam standard; vibration sensitive
TurbineClean liquid, gasLowYesHigh accuracy; bearing wear
CoriolisLiquid, gasMediumNoneMost accurate, mass flow; costly
UltrasonicLiquidNoneNoneClamp-on needs no pipe cut
Table 1 — General characteristics of flow-metering technologies
020406080100120Turndown ratio (to 1)4Orifice100Magnetic30Vortex15Turbine100Coriolis50Ultrasonic
Figure 1 — Typical turndown ratio; the larger the number, the wider the measuring range.
Orifice1.5 %Magnetic0.5 %Vortex1 %Turbine0.5 %Coriolis0.1 %Ultrasonic1 %
Figure 2 — Typical accuracy (± % of reading). Values are common catalogue figures and depend on the model.

Straight run and installation

Most velocity-based meters need an undisturbed flow profile. As a rule 10 pipe diameters of straight run upstream and 5 downstream are required, more for an orifice after an elbow or a part-open valve.

Tip
For steam consumption metering and cost allocation, a vortex meter with temperature and pressure compensation usually gives the best balance of accuracy and cost.

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