wtw pH 7310 - Page 60

What to do if... pH 7310
60 ba75929e02 10/2011
No stable measured
value
Obviously incorrect
measured values
Cause Remedy
pH electrode:
– Junction contaminated – Clean junction
– Membrane contaminated – Clean membrane
Test sample:
– pH value not stable – Measure with air excluded if
necessary
– Temperature not stable – Temper if necessary
Electrode + test sample:
– Conductivity too low – Use suitable electrode
– Temperature too high – Use suitable electrode
– Organic liquids – Use suitable electrode
Cause Remedy
pH electrode:
– pH electrode unsuitable – Use suitable electrode
– Temperature difference between
buffer and test sample too great
– Adjust temperature of buffer or
sample solutions
– Measurement procedure not suit-
able
– Follow special procedure