10 Troubleshooting
FLUXUS G831ST-HT
10.2 Measuring point selection
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UMFLUXUS_G831ST-HTV1-0EN, 2021-06-01
10.2
Measuring point selection
• Make sure that the recommended min. distance to any disturbance 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
The entered pipe roughness is not appropriate
• Check the entered value. The pipe state should be considered.
The pipe lining may cause problems during the measurement if it is not firmly attached to the inner pipe wall or
consists of an acoustically absorbing material
• Try to measure on a section of the pipe free from lining.
10.5
Significant deviations of the measured values
The defined upper limit of the flow velocity is too low.
• All measured flow velocities that are greater than the upper limit will be ignored and marked as invalid. All quantities
deviated from the flow velocity will also be indicated as invalid. If several correct measured values are ignored, the
totalizer values will be too low.
The entered cut-off flow is too high.
• All flow velocities below the cut-off flow are set to zero. All derived quantities are also set to zero. The cut-off flow has to
be set to a low value to be able to measure at low flow velocities (default: 2.5 cm/s).
The entered pipe roughness is not appropriate.
The flow velocity of the fluid is outside the measuring range of the transmitter.
The measuring point is not appropriate.
• Check whether a different measuring point provides better results. Because pipes are never rotationally symmetric, the
flow profile is affected.
10.6
Problems with the totalizers
The values of the totalizers are too small.
• One of the totalizers has reached the upper limit and has to be reset to zero manually.
The sum of the totalizers is not correct.
• The sum of both totalizers (throughput
Q
) transmitted via an output is not valid after one of the totalizers has overflowed
for the first time.
An interrogation point is displayed after the value of the totalizer.
• The measurement was temporarily impossible, therefore the totalizer value can be wrong.
