Dynasonics 902_903 Series Portable Doppler Ultrasonic Flow Meter - Manual (Page 8)

Rev. 10/08
- 6 - D902/3
PART 1 - INTRODUCTION
The D902/3 ultrasonic flow meter is designed to measure
the fluid velocity of liquid within closed conduit. The
transducers are a non-contacting, clamp-on type, which
will provide benefits of non-fouling operation and ease of
installation.
The flow meter operates by transmitting an ultrasonic
sound from its transmitting transducer through the pipe
wall into the flowing liquid. The sound will be reflected by
suspended particles or bubbles within the liquid and
recorded by the receiving transducer. A frequency shift
(Doppler effect) will occur that is directly related to the
speed of the moving particle or bubble. This shift in
frequency is interpreted by the instrument and converted to
various user defined measuring units.
A unique feature of this product is that it employs a
proprietary digital filtering system and recognition circuit.
This feature allows the instrument to measure fluid
velocities of clean liquids if the transducers are mounted
downstream from a 90
° elbow. The non-symmetrical
hydraulic turbulence which occurs downstream of an elbow
is captured, linearized and can be displayed as liquid
velocity and volume. This capability is not available in
conventional Doppler technology.
The D902/3 flow meter can be successfully applied on a
wide range of metering applications. The simple to program
transmitter allows the standard product to be used on pipe
sizes ranging from 1 - 120 inch (25 - 3048 mm) pipe I.D.
With the small pipe transducer option, the pipe size range
is 0.25 - 1 inch (6 - 25 mm). A variety of liquid applications
can be accommodated: raw sewage, reclaimed water,
cooling water, river water, plant effluent, mining slurries,
sludge, etc. Because the transducers are non-contacting
and have no moving parts, the flow meter is not affected
by system pressure, fouling or wear. Standard transducers
are rated to 250 °F (121 °C). Optional high temperature
transducers are rated to operate to 400 °F (204 °C).
General
Application Versatility