Metrohm 6.1115.000, Руководство пользователя

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5 Troubleshooting
Optrode
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13
5 Troubleshooting
Problem Cause Remedy
Signal jumps. No
endpoint. Several
endpoints. Erratic
signal changes of
the measuring
curve. Air bubbles enter the mea-
suring gap.
￭
Decrease the stirring rate.
￭
Make sure you are using degassed (CO
2
-
free) water.
￭
Glass vessels facilitate visual checking.
￭
Position the sensor in the sample vessel as
described in
Chapter 3.5, page 7 .
Stirring is inadequate.
￭
Adjust the stirring rate (take the beaker size
into account!).
￭
Position the sensor facing the stirrer stream
as described in
Chapter 3.5, page 7 .
The sample is not com-
pletely dissolved. Make sure that salts are completely dissolved
before adding indicator.
The sensor is not stable in
the titration head. Avoid strain on the sensor cable (automation!).
The stirring rate is too high
or too low. Adjust the stirring rate to the beaker size.
The indicator solution is
too old. Check the stability (usable just for one day, in
some cases). Prepare fresh solution, if neces-
sary.
Addition of the indicator
solution.
￭
Do not add indicator before the sample has
completely dissolved.
￭
After the addition of indicator, start with
the titration right away.
￭
Adjust the amount of indicator to the sam-
ple amount / fill volume.
No light. None of
the LEDs are lit up. There is no power supply
to the Optrode.
￭
Connect the Optrode to a USB port on a
titrator or a USB power supply unit.
￭
Check the USB cable.
The Optrode is defective. Replace the Optrode.