Siemens Sitrans LR250 Instruction Manual page 115

Symptom
Reading erratic
Reading response
slow
Reads correctly but
occasionally reads
high when vessel is
not full
Level reading lower
than material level
7ML19985JF02 SITRANS LR250 (PROFIBUS PA) – INSTRUCTION MANUAL
Operation Troubleshooting (cont'd)
Cause
echo confidence weak
liquid surface vortexed
material filling
Fill Rate (2.2.6.2.) setting is
incorrect
• detecting close range
echo
• build up near top of ves-
sel or nozzle
• nozzle problem
• material is within Near
Range zone
• multiple echoes pro-
cessed
• vessel near empty and
low dK material
Action
• refer toEcho Confidence (2.2.3.6.1.)
• use Auto False Echo Suppression
(2.2.4.2.) and Auto Suppression
Range (2.2.4.3.)
• use foam deflector or stillpipe
• decrease Fill Rate (2.2.6.2.)
• relocate instrument to side pipe
• increase confidence threshold in
Echo Threshold (2.2.3.1.2.)
• re-locate SITRANS LR250
• increase measurement response if
possible
• clean the antenna
• use Auto False Echo Suppression
(2.2.4.2.) and Auto Suppression
Range (2.2.4.3.)
• decrease Near Range (2.2.3.5.1.) (min-
imum value depends on antenna
type)
• raise SITRANS LR250
• ensureAlgorithm (2.2.3.1. 1 .) is set to tF
(trueFirst echo)
• ensure Material (2.2. 1 .2.) selection is
LIQUID LOW DK
• set Position (2.2.3.1.3.) to Hybrid
• check the setting for CLEF Range
(2.2.3.4.1.): see the table below Propa-
gation Factor (2.2.1.1.) for recom-
mended settings
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