Pros and cons of common types of flow measurement technology.
07/30/2018

Learn about the strengths and liabilities of different types of flow meters. Information courtesy of previous Pumps & Systems articles, primarily by Badger Meter and Ray Hardee Differential Pressure Pros

  • well understood
  • no moving parts
  • not greatly affected by viscosity changes
Cons
  • limited accuracy and turndown
  • complex installation requirements
Coriolis Pros
  • handles viscous or difficult fluids that don’t work well with other measurement technologies
  • no internal moving parts
  • minimum upkeep once installed
Cons
  • expense
  • sometimes considered too sophisticated
Electromagnetic Pros
  • no moving parts
  • low pressure drop
  • high accuracy
  • can handle range of viscosity, temperature and pressure
Cons
  • tendency to foul
  • heavy weight
  • expense
Positive Displacement (PD) Pros
  • highly accurate
  • easy to maintain
  • does not require straight pipe lengths
Cons
  • only clean fluids
  • large size
  • difficult to install
Thermal Mass Pros
  • low purchase cost
  • works well with gases
Cons
  • low to medium accuracy
Turbine Pros
  • high accuracy
  • wide turndown
  • repeatable measurements
Cons
  • only clean fluids
  • requires recalibration and service
Impeller Pros
  • universal mounting
  • relatively low cost
Cons
  • only clean, low-viscosity fluids
  • requires higher fluid velocity
Ultrasonic Pros
  • can be used with corrosive fluids or gases
  • unaffected by changes in temperature, viscosity, density or pressure
Cons
  • much less dependable at low flow rates
  • sensitive to unknown piping variables
Variable Area Pros
  • simple
  • inexpensive
  • reliable
Cons
  • must be mounted perfectly vertical
  • needs to be calibrated
  • relatively low accuracy
Vortex Pros
  • no moving parts
  • no regular maintenance
Cons
  • only clean liquids
  • may introduce pressure drop

Issue

July 2018