10 Troubleshooting
FLUXUS G809
10.1 Problems with the measurement
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UMFLUXUS_G809V2-2EN, 2020-06-25
10.1
Problems with the measurement
A measurement is not possible because no signal is received. A question mark is displayed after the physical
quantity.
• Check whether the entered parameters are correct, especially the outer pipe diameter, the pipe wall thickness and the
sound speed of the fluid. Typical errors: The circumference or the radius was entered instead of the diameter. The inner
pipe diameter was entered instead of the outer pipe diameter.
• Check the number of sound paths.
• Make sure that the recommended transducer distance was adjusted when mounting the transducers.
• Make sure that an appropriate measuring point is selected and the number of sound paths was entered correctly.
• Try to establish a better acoustic contact between the pipe and the transducers.
• Enter a lower value for the number of sound paths. The signal attenuation might be too high due to a high fluid viscosity
or deposits on the inner pipe wall.
The measuring signal is received but no measured values can be obtained
• A exclamation point (
!
) in the lower line on the right indicates that the defined upper limit of the flow velocity is exceeded
and, therefore, the measured values are marked as invalid. The limit has to be adapted to the measuring conditions or
the check has to be deactivated.
• If no exclamation point is displayed, a measurement at the selected measuring point is impossible.
Signal loss during the measurement
• If the pipe was without any pressure and no measuring signal has been received, contact FLEXIM.
• Wait a moment until the acoustic contact is reestablished. The measurement can be interrupted by a temporarily high
portion of liquid and solids in the fluid.
The measured values substantially differ from the expected values
• Wrong measured values are often caused by wrong parameters. Make sure that the entered parameters are correct for
the measuring point.
10.2
Measuring point selection
• Make sure that the recommended min. distance to any disturbance source is observed.
• Avoid measuring points with deposit formation in the pipe.
• Avoid measuring points in the vicinity of deformations and defects on the pipe as well as welds.
• Make sure the pipe surface at the selected measuring point is even.
• Measure the temperature at the measuring point and make sure that the transducers are suitable for this temperature.
• Make sure that the outer pipe diameter is within the measuring range of the transducers.
• When measuring on a horizontal pipe, the transducers have to be mounted laterally on the pipe.
10.3
Maximum acoustic contact
see section 6.2
10.4
Application-specific problems
A fluid with a wrong sound speed was selected
If the selected sound speed in the fluid does not match the actual one, the transducer distance can probably not be deter
-
mined correctly.
The fluid sound speed is used to calculate the transducer distance and is therefore very important for the transducer posi
-
tioning. The sound speeds stored in the transmitter only serve as an orientation.
The entered pipe roughness is not appropriate
Check the entered value. The pipe state should be considered.
Measurements on pipes made of porous materials (e.g., concrete or cast iron) are only conditionally possible
Contact FLEXIM.
The pipe lining may cause problems during the measurement if it is not firmly attached to the inner pipe wall or
consists of acoustically absorbing material
Try to measure on a section of the pipe free from lining.
