Flow & Entrained Air

Flow & Entrained Air

CiDRA SONARtrac Flow & Entrained Air Monitoring System

Non-contact passive sonar technology for dual measurement in liquids and slurries

Patented passive sonar, non-contact technology provides dual measurement capability of the volumetric flow and air content in slurries and liquids. This unique combination finally enables true phase fraction management leading to unprecedented improvement in process efficiencies and operations. Whether used to correct total volumetric flow in bubbly flows, correcting the measurement error in density meters for a more accurate mass balance or to early detect the cause of process upsets, SONARtrac PFM delivers both top and bottom line value for thousands of customers around the world.

SONARtrac measuring principle:

The volumetric flow and entrained air measurement system utilises an array of sensors that are wrapped around the pipe. The flow rate and percent of air by volume is determined using patented array processing techniques and are available as meter outputs. Liquid flow rate is measuremed by analysing the flow turbulence in the process stream, while the sound field is used to determine the sound speed, or velocity at which sound propagates through the process medium. The entrained air percentage is then calculated directly from the measured sound speed.


  • Quick, simple installation with no alignment or coupling gels required
  • Installs with a running process.  No need for process shutdown
  • No moving parts, no inherent drift mechanism
  • No recalibration
  • Maintenance free
  • Installs on any pipe materialFor additional information please feel free to contact our team directly.
ROC Instrumentation Flow & Entrained Air