User's Manual

Diagnosing and troubleshooting
10.3 Operation troubleshooting
SITRANS LR250 (PROFIBUS PA)
Operating Instructions, 01/2014, A5E32221386-AB
167
Symptom
Cause
Action
Reading erratic echo confidence weak
• refer to
Confidence (2.5.9.1.)
• use
Auto False Echo Suppression (2.5.10.1.)
and
Auto
False Echo Suppression Range (2.5.10.2.)
• use foam deflector or stillpipe
liquid surface vortexed
• decrease
Fill Rate (2.3.8.2..)
• relocate device to side pipe
• increase confidence threshold in
Echo Threshold (2.5.7.3.)
material filling
• Re-locate SITRANS LR250
Reading response
slow
Fill Rate (2.3.8.2.)
setting
incorrect
• increase measurement response if possible
Reads correctly but
occasionally reads
high when vessel is
not full
• detecting close range echo
• build up near top of vessel or
nozzle
• nozzle problem
• clean the antenna
• use
Auto False Echo Suppression (2.5.10.1.)
and
Auto
False Echo Suppression Range (2.5.10.2.)
Level reading lower
than actual material
level
• material is within Near Range
zone
• multiple echoes processed
• decrease
Near Range (2.5.1.)
(minimum value depends on
antenna type)
• raise SITRANS LR250
• ensure
Algorithm (2.5.7.1.)
is set to t
F
(First echo)
• vessel near empty and low
dK material
• ensure
Material (1.2.)
selection is LIQUID LOW DK
• set
Position Detect (2.5.7.2.)
to
Hybrid
• check the setting for
CLEF Range (2.5.7.4.):
see the table
below
Propogation Factor (2.5.3.)
for recommended
settings