wtw Multi 3430 - Dissolved Oxygen Troubleshooting

What to do if... Multi 3430
102
ba75865e08 06/2010
No stable measured
value
Obviously incorrect
measured values
6.3 Dissolved oxygen
Error message,
OFL
Cause Remedy
IDS pH sensor:
– Junction contaminated – Clean junction
– Membrane contaminated – Clean membrane
Test sample:
– pH value not stable – Measure with air excluded if
necessary
– Temperature not stable – Adjust temperature if neces-
sary
IDS pH sensor + test sample:
– Conductivity too low – Use suitable IDS pH sensor
– Temperature too high – Use suitable IDS pH sensor
– Organic liquids – Use suitable IDS pH sensor
Cause Remedy
IDS pH sensor:
– IDS pH sensor unsuitable – Use suitable IDS sensor
– Temperature difference
between buffer and test sample
too great
– Adjust temperature of buffer
or sample solutions
– Measurement procedure not
suitable
– Follow special procedure
Cause Remedy
– Measured value outside the
measuring range
– Select a suitable measuring
medium