Error
Possible cause
Remedy
Equipment need, spare parts,
information
Display value
implausible / no or
creeping change of
display
– No or incorrect sensor calibration
Calibration with original sample
required for concentration or solids
concentration
See chap. 5.10
– Sensor soiled
– Clean sensor
– Remove coarse coats mit brush
– Remove carbonates and similar
coats with 3% hydrochlorid acid
– Remove organic coats and
grease with oxidation agents
and / or grease solvents.
– Use spray cleaning
See instructions of assembly used
for spray cleaning
– User wiper version
Retrofitting possible: “wiper
retrofitting” service kit 50089254
– Wiper rubber defective
Replace wiper arm
“Wiper arm” service kit 50089252
– Sensor installed in “dead” zone
or air cushion in assembly or
flange
Check installation conditions, move
sensor in area with optional flow
conditions. Caution if installed in
horizontal lines!
– Incorrect sensor orientation
Orient sensor:
– Measuring surface should face
flow in normal media.
– Orient meas. surfacre at 90° to
flow in media with high solids
concentration
Frontal “bombardment” of
measuring surface with highly
viscous solids may result in an
adhering coating.
Incorrect temperature
value
– Temperature sensor defective
If temperature display is required:
replace sensor
Turbidity measurement itself does
not require temperature meas.
Controller or timer
cannot be activated
– No relay module installed
Install LSR1-2 or LSR1-4 module
See chap. 8.2 and 8.3
Controller / limit
contactor does not work
– Controller switched off
Activate controller
See chap. 5.5 or fields R2xx
– Controller in “Manual / Off” mode
Choose “Auto” or “Manual/On” mode
Keyboard, REL key
– Pickup delay setting too long
Disable or shorten pickup delay
See fields R2xx
– “Hold” function active
“Autom. hold” during calibration,
“hold” input activated;
“hold” via keyboard active
See fields S2 to S4
Controller / limit
contactor works
continuously
– Controller in “Manual / On” mode
Set controller to “Manual / Off” or
“Auto”
Keyboard, REL and AUTO keys
– Dropout delay setting too long
Shorten dropout delay
See fields R2xx
– Control loop interruption
Check measured value, current
output or relay contacts, actuators,
chemical supply
No turbidity current
output signal
– Line open or short-circuited
Disconnect line and measure
directly on instrument
mA meter 0–20 mA DC
– Total load in current loop
excessive (> 500
Ω
)
Disconnect line and measure
directly on instrument
Ohmmeter
– Output defective
See diagnosis table in chap. 8.1
– Instrument with
PROFIBUS-PA/-DP
PA-/DP instruments have no
current output!
Fixed current output
signal
– Current simulation active
Switch off simulation
See field O2(2)
– Processor system out of sync
Switch instrument off and back on
EMV problem: check installation if
problem persists
Incorrect current output
signal
– Incorrect current assignment
Check current assignment:
0–20 mA or 4–20 mA?
Field O2(1), O2(3) for table
– Total load in current loop
excessive (> 500
Ω
)
Disconnect output and measure
directly on instrument
Ohmmeter
Current output table not
accepted
– Value interval too small
Use sensible intervals
UM253E07.CHP
Liquisys M CUM 223 / 253
Maintenance and troubleshooting
Hauser
57