Siemens SITRANS LUT400 Operating Instructions Manual page 246

Symptom
Reading is fixed, but
material level changes
or reading does not fol-
low material level
Page 238 SITRANS LUT400 (HART) – OPERATING INSTRUCTIONS
Cause
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
Transducer mounting: wrong
location or incorrectly mounted
Incorrect transducer used for
the application
Unavoidable false echoes from
obstructions
Action
Verify response speed setting is
adequate for process. See
Response Rate
(set in the Quick
Start Wizard).
Check Noise, Echo Strength, Con-
fidence. See Echo Quality (3.2.9.)
on page 204.
Check LOE Timer is not set too
short. See LOE Timer (2.4.2.) on
page 144.
Ensure agitator is running.
Eliminate source of foaming.
Use stilling well
Set algorithm to default. If no
improvement, try a different algo-
rithm. See Algorithm (2.12.2.1.) on
page 182.
Ensure beam has a clear path to
material surface;
Verify transducer is not too tight;
Use an isolation coupling.
Use correct transducer. Contact
your Siemens representative.
Relocate transducer to ensure
beam has a clear path to material
surface;
Use manual TVT shaping or Auto
False Echo Suppression. See TVT
Shaper (2.12.4.) on page 185 or
Auto False Echo Suppression
(2.12.3.1.) on page 184.
A5E33329501