wtw pH/ION 7320, Operating Manual, Page: 90 / 104

What to do if... pH/ION 7320
90
ba75935e04 12/2017
No stable measured
value
Obviously incorrect
measured values
Cause Remedy
pH electrode:
– Junction contaminated – Clean the junction
– Membrane contaminated – Clean the membrane
Test sample:
– pH value not stable – Measure with air excluded if
necessary
– Temperature not stable – Temper if necessary
Ele test sample:
– Conductivity too low – Use a suitable electrode
– Temperature too high – Use a suitable electrode
– Organic liquids – Use a suitable electrode
Cause Remedy
pH electrode:
– pH electrode unsuitable – Use a suitable electrode
– Temperature difference between
buffer and test sample too great
– Adjust the temperature of buf-
fer or sample solutions
– Measurement procedure not suit-
able
– Follow a special procedure