Dynasonics D300_301 Series Doppler Ultrasonic Flow Meter - Manual (Page 5)

Rev. 2/00 -1.4- 300/301
The Dynasonics D300/301 flowmeter is designed to
measure the flow of liquids and slurries in full-pipe
closed systems. The transmitter is factory configured
to measure flow on a specific, customer specified,
pipe, where flow range and measuring units have
been supplied to the Dynasonics factory during
assembly and factory calibration. The standard
product is typically used on pipe sizes ranging from
1 - 120 inch [ 25 - 1524 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: sewage,
sludges, concrete, mining slurries, dredging, 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].
The basic principle of operation is the measurement
of the frequency shift “Doppler” of a reflected
ultrasonic signal from discontinuity in the flowing
liquid. In theory, these discontinuities can be virtually
any amount of suspended bubbles, solids, or
interfaces caused by turbulent flow. In practice the
degree to which this can be reliably accomplished is a
function of the sensitivity and frequency of the
transducer and associated transmitter. The
D300/301 design requires greater than 100 PPM of
suspended solids or bubbles over 100 microns in
size. Should your application be cleaner than this,
please check with factory for information on transit
time ultrasonic flowmeters. The transducer which
generates and receives the ultrasonic signal supplies
the data to the transmitter. The transmitter processes
the signal and provides an analog and pulse output
for velocity indicating and volumetric totalizing. In
addition, the transmitter contains a signal light which
determines satisfactory operation.
PART 1 - GENERAL
General
Operating Theory