Fault Inspection During C- Redox Measurement - Ecolab MULTRONIC Manuel Technique

6

Fault inspection during C- redox measurement

Fault symptom
Display constantly shows
one of the respective final
values of the
measurement range
Measuring value
indication unstable
Measuring value
indication jumps by
several digits
Error message
'plausibility error' during
calibration
Error message 'time out
error' during calibration
Indication does not move
to value of buffer solution
during calibration
The indication in the
buffer solution is OK, the
measured value in the
measurement water
changes
Indication too slow
417101806_Anhang04_Redox.doc
Redox Measuring Module
Cause / fault
Connecting lead measuring cell –
measurement amplifier
disconnected, i.e. short-circuited
Air in the measurement water
Lead from the measuring cell
defective
Wrong calibration solution
Measuring chain too slow
Strong measured value fluctuations See error description 'strong
Electrode too slow during
calibration
Old measuring chain
Earth fault in the signal output
circuit (0-20 mA)
Long measuring lead
Rectification
Check connecting lead and establish
connection
The measurement water supply, i.e.
extraction connection must be
adjusted in such a way that no air
bubbles can get into the measuring
cell
Check whether the shield is properly
connected. If necessary employ
double shielded cable.
Use correct buffer
See error description 'indication too
slow'
measured value fluctuations'
See error message 'indication too
slow'
Replace measuring chain
Check signal output circuit for earth
fault; use zero-potential measuring
module
If possible, reduce distance
- 43 - Rev.: 06-07/10