Ultrasonic flowmeters


  • Non-invasive, so no pressure drop
  • Measures flow of fluids and slurries that ordinarily cause damage to conventional sensors
  • Responds quickly to changes in velocity
  • Eliminates local mechanical and electrical noise, permitting use in a variety of locations
  • Works with a variety of pipe sizes and flow conditions
  • Accommodates flow in either direction
  • Measures independently of temperature, pressure, density, viscosity, and electrical conductivity
  • Non-contact, lack of moving parts greatly reduce maintenance requirements and sensor fouling
  • Easy installation.


  • Doppler: can’t measure gas flow
  • Time-of-travel: requires relatively clean fluid
  • Excess solids or entrained gases may block ultrasonic pulses
  • Requires steady flow, can’t handle wide and/or rapid fluctuations