Two transmitters, which
operate as both transmitters and receivers, are placed on the outside of a
pipe—one upstream and one downstream. Each transmitter simultaneously
sends a high frequency sound wave to the other. The signal moving in the
direction of the flow travels faster than the signal moving against the
flow. The difference in the transit time is translated with advanced
electronics into a flow rate.
Technology
Advantage
Disadvantage
Fluids
Fluid velocity measured
by time arrival difference of sound waves from upstream and downstream
transducers
This flow meter is a
non-invasive, ultrasonic flow metering system that uses two transducers
mounted side by side, operating as ultrasonic signal transmitters and
receivers. Based on the principles of the Doppler effect, it calculates
flow velocity by sensing and measuring the frequency shift in motion from
suspended particles or bubbles within a liquid.
Technology
Advantage
Disadvantage
Fluids
Fluid velocity measured
by sensing signals from reflective materials within the liquid and
measuring the frequency shift due to the motion of these reflective
materials
Low-cost, clamp-on installation
Non-intrusive
Measures liquids containing particulates or
bubbles
Low maintenance
Best for larger pipes
Can't be used in clean liquids
Less accurate than in-line or transit-time
ultrasonic
