Product Manual

Wall Mounted Ultrasonic Flowmeter---User Manual
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(2) Try to polish the outer surface of the pipe, and apply more couplant to increase the signal
strength.
(3) Tenderly adjust the position of the two transducers, both vertically and horizontally, while
checking the signal strength. Stop at the position where the signal strength reaches to
maximum. Then, check the transducer spacing to make sure it is the same as or very close to
what window M25 shows.
(4) If the installation method is V-method and the pipe is big, use may need to try Z-method in
order to get stronger signal.
2.7.2. Signal Quality
Signal quality is indicated as the Q value in the instrument. A higher Q value would mean a higher
signal to Noise Ratio (SNR), and accordingly a higher degree of accuracy able to be achieved.
Under normal pipe condition, the Q value is in the range of 60-99, the higher the better.
Causes for a lower Q value could be:
(1) Interference from other instruments and devices nearby, such as a power frequency transverter
which could cause strong interference. Try to relocate the flow meter to a new place where the
interference can be reduced.
(2) Bad sonic coupling between the transducers and the pipe. Try to polish the pipe surface again,
clean the surface and apply more couplant, etc.
(3) The selected pipe section is difficult to conduct the measurement. Relocate to a more favorable
pipe line.
2.7.3. Total Transit Time and Delta Time
The total transit time (or traveling time) and the delta time are displayed on menu window M93.
They are the primary data for the instrument to calculate the flow rate. Therefore, the measured
flow rate will vary as the total transit time and delta time vary.
The total transit time should remain stable or vary in a very small range.
The delta time normally varies less than 20%. If the variation exceeds 20% in either positive or
negative direction, there could be certain kinds of problems with the transducer installation. The
user should check the installation for sure.
2.7.4. Transit Time Ratio
Transit-time ratio R is usually used to check whether the transducer installation is good and
whether the entered pipe parameters are in consistency with their actual values. If the pipe
parameters are correct and the transducers are installed properly, the transit time ratio should be in
the range of 100±3%.Particalarly, when the flow is stand-still, the ratio should be very close to
100%. If this range is exceeded, the user should check:
1) If the entered pipe parameters are correct?