Flexim FLUXUS WW, User Manual

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FLUXUS WW 17 Troubleshooting
124 UMFLUXUS_WWV1-1EN, 2018-02-28
17.5 Large deviations of the measured values
The entered sound speed of the fluid is wrong
A wrong sound speed can result in the ultrasonic signal that is reflected directly on the pipe wall being mistaken for the
measuring signal that has passed through the medium. The flow calculated on the basis of the wrong signal by the trans-
mitter is very small or fluctuates around zero.
There is gas in the pipe
If there is gas in the pipe, the measured flow will always be too high because both, the gas volume and the liquid 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 devi-
ated 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 (default:
2.5 cm/s) has to be set to a low value to be able to measure at low flow velocities.
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. Change the transducer position.
17.6 Problems with the totalizers
The values of the totalizers are too high
See
Special Funct.\SYSTEM settings\Measuring\Quantity recall
. If this menu item is activated, the values
of the totalizer will be stored. The totalizer will continue with this value at the start of the next measurement.
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
See
Special Funct.\SYSTEM settings\Measuring\Quant. wrapping
. The sum of both totalizers (throughput)
transmitted via the output is no longer valid after the first overflow of one of the totalizers.
17.7 Data transmission
The file with the transmitted measuring data contains meaningless strings
The transmission data of the transmitter and the terminal program are not identical. Set the transmission parameters of
the transmitter (see section 13.2.4) and the terminal program.