Siemens Sitrans LR250, Руководство по эксплуатации, Страница: 179 / 306

Diagnosing and troubleshooting
10.4 Operation troubleshooting
SITRANS LR250 (PROFIBUS PA)
Operating Instructions, 08/2014, A5E32221386-AC
177
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 tF (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