wtw inoLab Multi 9620 IDS Operating Manual page 126

What to do if...
No stable measured
value
Obviously incorrect
measured values
126
Cause
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 suit-
able
®
inoLab Multi 9620 IDS
Remedy
– Clean the junction
– Clean membrane
– Measure with air excluded if
necessary
– Adjust temperature if necessary
– 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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