Emerson Rosemount 5408 Reference Manual page 101

Reference Manual
00809-0100-4408, Rev BA
(1)
Symptom
Measured level fluctuates.
Measured level is occasionally unstable.
Measured level lags during rapid level
changes.
Incorrect level when using still pipe.
Service and Troubleshooting
Possible causes
Excessive foaming or
turbulence.
Time
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
Service and Troubleshooting
Recommended actions
Under turbulent conditions with low level rates,

consider increasing the Damping value, see
"Damping value" on page
Enable the Foam parameter or Turbulent Surface

parameter, or both. See "Process conditions" on
page 196.
If two surfaces are seen in foamy applications,

set Double Surface Handling to Track Lower
Surface. See "Double surface handling" on
page 201.
Analyze the echo curve and check amplitude
thresholds, see "Set amplitude thresholds" on
page 96.
If possible, remove the disturbing object.
If there is a problem with lag during rapid level
changes, consider decreasing the Damping value,
see "Damping value" on page
Verify Maximum Level Rate configuration.
Enable pipe measurement, see
on page 192.
Verify the configured Pipe Inner Diameter
matches the physical inner diameter.
Enable the Track First Echo function, see
"Handling ghost echoes in still pipes" on
page 110.
November 2017
187.
187.
"Mounting type"
89