Other Possible Errors - Ph Measurement - wtw pH 340/ION Instruction Manuals

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Other possible errors - pH measurement

System message
Voltage of pH
electrode not stable
Measured values
obviously wrong
62
Cause
pH electrode:
• Diaphragm contaminated
• Membrane contaminated
Sample solution:
• pH value not stable
• Temperature not stable
Electrode + sample
solution:
• Conductivity too low
• High temperature
• Organic fluids
pH electrode:
• Unsuitable pH electrode
• Temperature difference
between calibration and
sample solution too high
• Interference voltages
• Unsuitable measuring
procedure
Troubleshooting
Action
pH electrode:
Clean diaphragm
Clean membrane
Sample solution:
Measure in an airproof vessel
if necessary
Temper if necessary
Electrode + sample solution:
Use suitable pH electrode
Use suitable pH electrode
Use suitable pH electrode
pH electrode:
Select suitable pH electrode
Temper buffer or sample
solution
With grounded sample solution
do not use a grounded PC or
printer
Pay attention to special
procedures