Metrohm 851 Titrando - Manual (Page 54)

6.1 General
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46 ￭￭￭￭￭￭￭￭
851 Titrando
6 Troubleshooting
6.1 General
Problem Cause Remedy
The "On" LED is not
illuminated, even
though the instru-
ment is connected
to the power supply. The Touch Control or the
computer has not been
switched on yet or the
plugs are not correctly
plugged in. 1. Check the plug connections.
2. Switch on the Touch Control or the com-
puter.
6.2 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. Select the user-defined titration rate and
increase the minimum volume increment (see
manual/help of the software used).
The stop criterion is unsuit-
able. Adjust the control parameters (see manual/
help of the software used):
￭ Increase the stop drift.