Flexim FLUXUS F401, Руководство по эксплуатации

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10 Troubleshooting
FLUXUS F401 10.5 Significant deviations of the measured values
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UMFLUXUS_F401V2-1EN, 2020-06-12
A high concentration of gases or solids in the fluid scatter and absorb the
ultrasonic signal and thus attenuate the measuring signal
A measurement is impossible if the value is ≥ 10 %. If the proportion is high, but < 10 %,
a measurement is only conditionally possible.
10.5 Significant deviations of the measured values
A fluid with a wrong sound speed was selected
If a fluid was selected whose sound speed does not match the actual one, the measuring
signal may be confused with the pipe wall signal.
The flow calculated on the basis of the wrong signal by the transmitter is very small or
fluctuates around zero.
There is gas in the pipe
If there is gas in the pipe, the measured flow will be too high because both, the liquid and
gas volume, are measured.
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 ve -
locities (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.