Siemens 7ML5431 Operating Instructions Manual page 173

Symptom
Reading response
slow
Reads correctly but
occasionally reads
high when vessel is
not full
Level reading lower
than actual material
level
SITRANS LR250 with mA/HART
Operating Instructions, 10/2019, A5E32220602-AG
Cause
liquid surface vortexed
material filling
Fill Rate per Minute (2.4.2.) set-
ting incorrect
detecting close range echo
•
build up near top of vessel or
•
nozzle
nozzle problem
•
material is within Near Range
•
zone
multiple echoes processed
•
vessel near empty and low
•
dK material
Action
decrease Fill Rate per Minute (2.4.2.)
•
relocate device to side pipe
•
increase confidence threshold in Echo Threshold (2.8.4.3.)
•
Re-locate SITRANS LR250
•
increase measurement response if possible
•
clean the antenna
•
use Auto False Echo Suppression (2.8.7.1.) and Auto
•
False Echo Suppression Range (2.8.7.2.)
decrease Near Range (2.8.1.) (minimum value depends
•
on antenna type)
raise SITRANS LR250
•
ensure Algorithm (2.8.4.1.) is set to F (First echo)
•
ensure Material (2.2.3.) selection is LIQUID LOW DK
•
set Position Detect (2.8.4.2.) to Hybrid
•
set CLEF Range (2.8.4.4.) to 0.5 m
•
Diagnosing and troubleshooting
10.4 Operation troubleshooting
173