Emerson Rosemount 5408 Reference Manual page 104

Service and Troubleshooting
Table 7-6: Incorrect Level Readings
(1)
Symptom
Measured level is occasionally unstable.
Measured level lags during rapid level
changes.
Incorrect level when using still pipe.
94
(continued)
Possible causes
May be caused by an empty
tank with the amplitude
threshold set too low.
The product surface is close
to a suppressed false echo.
Time
Damping value too high.
Maximum Level Rate value
too low.
Time
Device is not configured for
still pipe measurement.
Incorrect Pipe Inner Diameter
configuration.
Ghost echo problems below
the product surface.
Time
Recommended actions
Analyze the echo curve and check ampli-
tude thresholds, see Amplitude
If possible, remove the disturbing object.
If there is a problem with lag during rapid
level changes, consider decreasing the
Damping value, see Damping
Verify Maximum Level Rate configuration.
Enable pipe measurement, see
Mounting type.
Verify the configured Pipe Inner Diameter
matches the physical inner diameter.
Enable the Track First Echo function, see
Section 7.5.3 .
Reference Manual
thresholds.
value.