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Z method
If the pipe diameter is too large or the lining is too thick, it is recommended to use the Z method.
The signal transmitted after a Z-method installation has less attenuation than a signal transmitted
using the V method. This is because the Z method uses a directly transmitted (rather than
reflected) signal that passes through the medium only once. With the Z method, you can measure
on pipe diameters ranging from 100 to 5000 mm (4 ... 200 in.). Therefore, we recommend the Z
method for pipe diameters over 300 mm (12 in.).
6.2.3
Inspection
Verify that the sensors are properly installed and that there is an accurate and strong ultrasonic
signal that ensures proper operation and high reliability of the sensors. This can be confirmed by
checking the detected signal strength, the total transit time, the delta time as well as the transit
time ratio. The following inspections must be made to ensure high reliability of the measurement
and long-term operation of the device.
Signal strength
The signal strength can be checked in window M04. Here, you can see the strength of the signal
of both sensors. The signal strength is indicated by numbers from 00.0 to 99.9. 00.0 stands for
no detected signal, while 99.9 stands for the maximum signal strength. The stronger the detected
signal strength, the longer the device works reliably and the more stable the obtained measured
value will be. Position the sensors optimally and check whether sufficient coupling gel was applied
during installation to obtain the maximum signal strength. The system requires a signal strength
of more than 75.0 for both sensors. If the determined signal strength is too low, the position of the
sensors and the spacing should be re-adjusted and the pipe re-inspected. You can also change
the mounting method to rectify this problem.
© PCE Instruments
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