￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭￭
5 Troubleshooting
867 pH Module
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31
Problem
Cause
Remedy
The measuring chain is
defective.
Replace the measuring chain.
Sluggish measured
value setting.
The pH or ISE membrane or
the diaphragm is contami-
nated.
Clean the membrane or the diaphragm.
Insufficient slope
during calibration.
The pH or ISE membrane or
the diaphragm is contami-
nated.
Clean the membrane or the diaphragm.
No hydrated layer is pres-
ent on the glass membrane
after measurements in
water-free solutions.
Between measurements, place separate elec-
trodes in distilled water and combined elec-
trodes in reference electrolyte.
The buffer or standard
solutions are old.
Use fresh buffer or standard solutions.
The electrode is worn out.
Replace the electrode.
The Delta U poten-
tial step set is not
achieved with 'auto'
standard addition.
The streaming potential of
the indicator electrode or
reference electrode results
in a potential difference
between stirred addition
and non-stirred measure-
ment.
￭
Reduce the dosing rate.
￭
Increase the stirring rate.
￭
Increase
Delta U
.
￭
Touch Control:
Select
Addition
=
auto dos
.
