wtw Multi 3410 Operating Manual page 89

Multi 3410
No stable measured
Obviously incorrect
measured values
ba75863e02 12/2009
Cause
value
IDS pH sensor:
– Junction contaminated
– Membrane contaminated
Test sample:
– pH value not stable
– Temperature not stable
IDS pH sensor + test sample:
– Conductivity too low
– Temperature too high
– Organic liquids
Cause
IDS pH sensor:
– IDS pH sensor unsuitable
– Temperature difference
between buffer and test sample
too great
– Measurement procedure not
suitable
What to do if...
Remedy
– Clean the junction
– Clean membrane
– Measure with air excluded if
necessary
– Adjust temperature if neces-
sary
– Use suitable IDS pH sensor
– Use suitable IDS pH sensor
– Use suitable IDS pH sensor
Remedy
– Use suitable IDS sensor
– Adjust temperature of buffer
or sample solutions
– Follow special procedure
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