Metrohm 900 - Volumetric Karl Fischer Titration

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31 Troubleshooting
900 Touch Control
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487
Problem Cause Remedy
￭ Define Titration rate = user and reduce
the control range.
￭ Define Titration rate = user and increase
the maximum rate (Max. rate).
￭ Define Titration rate = user and increase
the minimum rate (Min. rate).
The results are
spread widely.
The minimum dosing rate is
too high.
Define Titration rate = user and reduce the
minimum rate (Min. rate) (see chapter 29.3.2,
page 312).
The control range is too
small.
Define Titration rate = user and increase the
control range.
The electrode responds too
slowly.
Replace the electrode.
31.8 Volumetric Karl Fischer Titration
Problem
Cause Remedy
The drift is very high
during conditioning.
The titration cell is leaking. ￭ Check the seals and the septum. Replace if
necessary.
￭ Replace the molecular sieve.
The drift becomes
greater after each
titration.
The sample releases water
very slowly.
￭ Adjust the method.
￭ Add solubility promoter.
￭ Increase the temperature (possibly using a
KF oven).
￭ See technical literature.
A side reaction is taking
place.
￭ Use special reagents.
￭ Adjust the method (increase/decrease the
temperature, external extraction).
￭ See technical literature.
The pH value is no longer
in the optimum range.
Add buffer, see technical literature.
The titration will not
be finished.
The titration cell is leaking. ￭ Check the seals and the septum. Replace if
necessary.
￭ Replace the molecular sieve.
The minimum increment is
too low.
Define Titration rate = user and increase the
minimum volume increment (Min. incre-
ment) (see chapter 29.4.2, page 325).