Siemens SITRANS L 7ML5400 Operating Instructions Manual page 277

Symptom
Display active, transducer not
pulsing
Reading fluctuates while materi-
al level is still
Reading is fixed, but material
level changes or reading does
not follow material level
SITRANS LUT400
Operating Instructions, 04/2021, A5E33329501-AG
Possible Cause
Incorrect transducer connections
or wiring;
Incorrect transducer selection
(or set to NO Transducer);
Transducer has been disabled
through the software
Material level is changing
Strong false echoes
Incorrect damping
Improper echo Algorithm selec-
tion
High noise levels
Weak echo
Foam on surface of material
Rapid temperature changes
Faulty temperature sensor
Vapors
Incorrect speed of response
Loss of Echo condition (LOE)
Agitator blade stopped in front
of transducer (false echo)
Foam on surface of material
Incorrect Algorithm used
Diagnosing and Troubleshooting
11.4 Common Problems Chart
Action
Verify terminal connections;
Check transducer field wiring;
Check any junction box connec-
tions;
Check that transducer is enabled
(see Transducer Enable (3.3.1.)
(Page 250))
Visually verify, if possible.
Determine source of false ech-
oes; Relocate transducer to
avoid source.
Adjust damping. See Damping
Filter (2.3.3.) (Page 178).
Set algorithm to default. If no
improvement, try a different
algorithm. See Algorithm
(2.12.2.1.) (Page 224).
Verify source and minimize. See
Noise Problems (Page 280).
Determine cause; Check noise,
confidence, FOM, and echo
strength. See Echo Quality
(3.2.9.) (Page 249).
Eliminate source of foaming;
Use stilling well.
Use an external temperature
sensor. See Temperature Source
(2.12.1.3.) (Page 222).
Verify operation;
Replace if required, or use fixed
temperature. See Temperature
Source (2.12.1.3.) (Page 222).
If fluctuation is unacceptable,
consider an alternative technol-
ogy. Contact your Siemens rep-
resentative.
Verify response speed setting is
adequate for process. See Quick
Start (Page 59) (set in the Quick
Start Wizard).
Check Noise, Echo Strength,
Confidence. See Echo Quality
(3.2.9.) (Page 249).
Check LOE Timer is not set too
short. See LOE Timer (2.4.2.)
(Page 179).
Ensure agitator is running.
Eliminate source of foaming.
Use stilling well
Set algorithm to default. If no
improvement, try a different
algorithm. See Algorithm
(2.12.2.1.) (Page 224).
277