TopCal S CPC 300
8 Troubleshooting
Hauser
119
Permanent, incorrect
measured value
Electrode not immersing or protec-
tive cap not removed
Check installation position, remove
protective cap.
Air cushion in assembly
Check assembly and installation
position.
Earth fault at or in the instrument
Test measurement in insulated ves-
sel, possibly with buffer solution.
Plastic vessel, buffer solutions.
Behaviour when instrument is con-
nected to process?
Hairline crack in glass membrane
Replace electrode.
pH electrode
Instrument in impermissible oper-
ating status (no response on
pressing key)
Switch instrument off and on.
EMC problem: If repeated, check
grounding and wire routing
Incorrect temperature
reading
Incorrect sensor connection
Check connections using wiring dia-
gram.
Wiring diagram s. page 18
Measuring cable defective
Check cable.
Ohmmeter
Incorrect sensor type selected
Set sensor type on instrument
(Field 141).
Check temperature sensor with
Ohmmeter.
Sensor defecitve
Check sensor
pH value in process
incorrect
No / incorrect temperature com-
pensation
ATC: Activate function
MTC: Set process temperature
Conductivity of medium too low
Select pH electrode with salt supply
or liquid KCl.
e. g. Orbisint CPS 11-xASxx
or Ceraliquid CPS 41
Flow rate too high
Reduce flow rate or measure in a
bypass.
Potential in medium
Possibly earth with / at PA pin (con-
nect PA to PE).
Problem mainly occurs in plastic
lines
Device unsymmetrical and PAL
connected
possibly earth with / at PA pin (con-
nect PA to PE)
Electrode soiled or with deposits
Clean electrode (see Chap. 8.8.1).
Highly polluted media:
Use spray cleaning.
Measured values
fluctuate
Interference in measuring cable
Connect cable screening as per wir-
ing diagram.
Wiring diagram s. page 18
Faults in signal
output line
Check line installation, possibly
route line separately.
Interference potential in medium
Symmetrical measurement (with
PML)
No potential matching (PA/PM)
With symmetrical measurement
Connect PA pin in assembly to
device terminal PA/PM.
Possibly earth medium by connect-
ing PA to PE
Error
Possible cause
Remedial action
Equipment needed, spare
parts
