Operation Troubleshooting - Siemens SITRANS LR250 Operating Instructions Manual

Operation Troubleshooting

Operating symptoms, probable causes, and resolutions (continued on next page).
Symptom
Display shows
S: 0 LOE
Display shows
S: 0 LOE
Display shows
S: 0 LOE
Display shows
S: 0 LOE
Reading does not
change, but the level
does
Measurement is con-
sistently off by a con-
stant amount
Screen blank
Page 142 SITRANS LR250 (FF) – OPERATING INSTRUCTIONS
Operation Troubleshooting
Cause
Level or target is out of
range
Material build-up on
antenna
Location or aiming:
• poor installation
• flange not level
• Auto False Echo
Suppression may be
incorrectly applied
Antenna malfunction:
• temperature too high
• physical damage
• excessive foam
• multiple echoes
SITRANS LR250 process-
ing wrong echo, i.e. vessel
wall, or structural member
• setting for Low
Calibration Point (2.3.7.1.)
not correct
• setting for Sensor Offset
(2.3.7.3.) not correct
Power error
Action
• check specifications
• check Low Calibration Point (2.3.7. 1 .)
• increase Confidence (2.5.9.1.)
• clean the antenna
• re-locate SITRANS LR250
• check to ensure nozzle is vertical
• ensure end of antenna protrudes
from end of nozzle
• review Auto False Echo
Suppression (2.5. 1 0.1.) on page 110
• ensure Auto Suppression Range is
set correctly
• check temperature in Maximum
Value (3.3.2.)
• use foam deflector or stillpipe
• relocate
• use a defoamer
• set Algorithm (2.5.7.1.) to tF (trueFirst
echo)
• re-locate SITRANS LR250
• check nozzle for internal burrs or
welds
• rotate instrument 90°
• use Auto False Echo Suppression
(2.5.10.1.) and Auto False Echo
Suppression Range (2.5.10.2.)
• check distance from sensor
reference point to Low Calibration
Point (2.3.7.1.)
• check Sensor Offset (2.3.7.3.)
• check nameplate rating against
voltage supply
• check power wiring or source
7ML19985KL01