TDS-100H Handhold Ultrasonic Flowmeter Ver.8.08 - 12 -
examples of optimum locations.
Principles to selection of an optimum location
(1)
Install the transducers on a longer length of the straight pipe. The longer the better, and
make sure that the pipe is completely full of liquid.
(2)
Make sure that the temperature on the location does not exceed the range for the
transducers. Generally speaking, the closer to the room temperature, the better.
(3)
Take the pipe fouling into consideration. Select a straight length of a relatively newer
pipe. If the condition is not satisfying, consider the fouling thickness as part of the liner
for a better result.
(4)
Some pipes have a kind of plastic liner, and between the outer pipe and the liner there
may be a certain thickness difference that will prevent the ultrasonic waves from direct
traveling. Such conditions will make the measurement very difficult. Whenever possible,
try to avoid this kind of pipes. If impossible, try our plug-in transducers that are installed
permanently on the pipe by drilling holes on the pipe while liquid is running inside.
§2.8 Transducers Installation
The transducers used by the TDS-100 series ultrasonic flow meter are made of piezoelectric
crystals both for transmitting and receiving ultrasonic signals through the wall of liquid piping
system. The measurement is realized by measuring the traveling time difference of the
ultrasonic signals. Since the difference is very small, the spacing and the alignment of the
transducers are critical factors to the accuracy of the measurement and the performance of the
system. Meticulous care should be taken for the installation of the transducers.
Steps to the installation of the transducers
(1)
Locate an optimum position where the straight pipe length is sufficient, and where pipes
are in a favorable condition, e.g., newer pipes with no rust and ease of operation.
(2)
Clean any dust and rust. For a better result, polishing the pipe with a sander is strongly
recommended.
(3)
Apply adequate coupler to the spot where the transducers are to be installed and leave
no gap between the pipe surface and the transducers.
Extra care should be taken to avoid any sand or dust particles left between the pipe outer
surface and the transducers.
To avoid gas bubbles inside the upper part of the pipe, the transducers should be installed
horizontally by the side of the pipe.
§2.8.1 Transducers Spacing
The spacing value shown on menu window M25 refers to the distance of inner spacing
between the two transducers. The actual transducers spacing should be as close as possible to
the spacing value.
§2.8.2 V-method Installation
V-method installation is the moswidely used mode for daily measurement with pipe inner
diameters ranging from 20 millimeter to 300 millimeter. It is also called reflective mode or
