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Troubleshooting
9.4 Operation troubleshooting
SITRANS Probe LR with mA/HART
Operating Instructions, 05/2019, A5E32337711-AC
79
Symptom
Cause
Action
too much load resistance
•
change barrier type, or
•
remove something from the loop, or
•
increase supply voltage
Reading erratic
echo confidence weak
•
refer to P805
•
use P837/P838
•
use foam deflector or stilling well
liquid surface vortexed
•
decrease measurement response P003
•
relocate instrument to side pipe
•
increase confidence threshold P804
material filling
re-locate SITRANS Probe LR
Reading response
slow
P003 setting
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
•
wrong antenna choice for
application
•
vessel nozzle problem
•
clean the antenna
•
longer shield required
•
use P837/P838
Level reading lower
than material level
•
material is within near
blanking zone
•
vessel near empty and low
ε
r
material
•
multiple echoes processed
•
decrease blanking P800: min. 0.3 m (1
ft) plus the shield length (if any)
•
raise SITRANS Probe LR
•
decrease range extension
•
ensure P820 is set to 12 (First echo)
nozzle too narrow for length
shielded antenna required: discuss with your
Siemens representative.
internal seam in nozzle
•
inspect and remove seam
•
use P837/P838
•
longer shield required