Flow rate measurement
In ultrasonic flow rate measurement a distinction is
made between two different measuring principles: The Doppler
effect and the analysis of the traveling wafe time. In
both cases a piezoceramic transmitter positioned on
the tube wall generates ultrasonic waves which are
transmitted into the liquid diagonally to the
direction of flow. With the Doppler effect, the
frequency shift of the ultrasonic waves,
which are reflected by stray particles in the liquid,
are evaluated. The greater the flow speed of the
liquid, the greater the frequency shift
between the radiated and the reflected wave front.
Only one piezo transducer sending and receiving
at different times is needed for this measuring method.
With the traveling wafe-time principle, two piezoceramic
transducers are always used. They are positioned
offset to the direction of flow. They send or receive
alternately pulse-shaped ultrasonic wave packages
against the direction of flow and in the direction
of flow. There is in each case a superimposition of
sound propagation speed and flow speed. The flow
speed is then proportional to the reciprocal value
of the propagation time difference in and contrary
to the direction of flow. The advantage of this
measuring method is that the measurement is independent
of the sound propagation speed and thus of the medium.
This allows not only liquids but also gases to be
measured.
Designs: Round disk
Material: SONOX® P 5, SONOX® P 502, SONOX® P 508