Operating Instructions

Symptom Cause Action
Display shows
6/2(
antenna malfunction:
● temperature too high
● physical damage
● excessive foam
● multiple echoes
● check Current Internal Temperature (3.2.1.)
● use foam deflector or stillpipe
● relocate
● use a defoamer
● set Algorithm (2.8.4.1.) to F (First echo)
Reading does not
change, but the level
does
SITRANS LR250 processing
wrong echo, for example, vessel
wall, or structural member
● re-locate SITRANS LR250
● check nozzle for internal burrs or welds
● rotate device 90°
● use Auto False Echo Suppression (2.8.7.1.)
● if necessary: see Auto False Echo Suppression (Page 228).
Measurement is con‐
sistently off by a con‐
stant amount
● setting for Low Calibration Pt.
(2.3.1.) not correct
● setting for Sensor Offset
(2.3.3.) not correct
● check distance from sensor reference point to Low
Calibration Pt. (2.3.1.)
● check Sensor Offset (2.3.3.)
Screen blank power error
● check nameplate rating against voltage supply
● check power wiring or source
too much load resistance
● change barrier type, or
● remove something from the loop, or
● increase supply voltage
● reduce wire distance or use larger gage wire
Reading erratic echo confidence weak
● refer to Confidence (2.8.6.1.)
● use Auto False Echo Suppression (2.8.7.1.) and Auto False
Echo Suppression Range (2.8.7.2.)
● use foam deflector or stillpipe
liquid surface vortexed
● decrease Fill Rate per Minute (2.4.2.)
● relocate device to side pipe
● increase confidence threshold in Echo Threshold (2.8.4.3.)
material filling
● Re-locate SITRANS LR250
Reading response slow Fill Rate per Minute (2.4.2.) set‐
ting incorrect
● increase measurement response if possible
Reads correctly but oc‐
casionally 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 (2.8.7.1.) and Auto False
Echo Suppression Range (2.8.7.2.)
Level reading lower
than actual material
level
● material is within Near Range
zone
● multiple echoes processed
● 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)
● vessel near empty and low dK
material
● 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
SITRANS LR250 with mA/HART
164 Operating Instructions, 10/2019, A5E32220602-AG