Siemens Sitrans LR250 - Response Rate (2.3.8.1.)

Page 108 SITRANS LR250 (PROFIBUS PA) – INSTRUCTION MANUAL 7ML19985JF02
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B: Troubleshooting
Operation Troubleshooting
Operating symptoms, probable causes, and resolutions (continued on next page).
Operation Troubleshooting
Symptom Cause Action
Display shows
S: 0 LOE
level or target is out of
range
• check specifications
•check Low Calibration Point (1.5.)
• increase Echo Confidence (2.2.3.6.1.)
Display shows
S: 0 LOE
material build-up on
antenna
• clean the antenna
• re-locate SITRANS LR250
Display shows
S: 0 LOE
location or aiming:
• poor installation
• flange not level
• Auto False Echo Suppres-
sion may be incorrectly
applied
• check to ensure nozzle is vertical
• ensure end of antenna protrudes
from end of nozzle.
• review
Auto False Echo Suppression
(2.2.4.2.) on page 114
• ensure Auto Suppression Range is
set correctly
Display shows
S: 0 LOE
antenna malfunction:
• temperature too high
• physical damage
• excessive foam
• multiple echoes
•check Maximum Internal Tempera-
ture (3.3.8.)
• use foam deflector or stillpipe
•relocate
• use a defoamer
•set Algorithm (2.2.3.1.1.) to tF (trueFirst
echo)
Reading does not
change, but the level
does
SITRANS LR250 process-
ing wrong echo, i.e. vessel
wall, or structural member
• re-locate SITRANS LR250
• check nozzle for internal burrs or
welds
• rotate instrument 90°
•use Auto False Echo Suppression
(2.2.4.2.) if necessary: see
Auto False
Echo Suppression (2.2.4.2.)
on page
114
Measurement is con-
sistently off by a con-
stant amount
• setting for Low Calibra-
tion Pt. (2.2.1.4.) not cor-
rect
• setting for Sensor Offset
( 2. 2.1.1 0. ) not correct
• check distance from sensor refer-
ence point to Low Calibration Pt.
(2.2.1.4.)
•check Sensor Offset (2.2.1.10.)
Screen blank
power error • check nameplate rating against volt-
age supply
• check power wiring or source