Voith BTG Mutek PCD-06, Руководство по эксплуатации

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© BTG 2021 Operation Manual Mütek
TM
PCD-06 51
VII. Maintenance
7.2.4 Checking the streaming potential
If a freshly cleaned measuring cell is filled with 10 ml of
anionic titrant 0.001 N repeatedly in succession, the
streaming potential measured should be roughly identi-
cal. Depending on the instrument, the streaming poten-
tial is generally between -1200 mV to +1800 mV.
If the cell is used very frequently, this value will diminish
over time due to wear. This does not affect titration
results.
However, if the streaming potential suddenly drops by
several 100 mV from one measurement to the next, the
measuring cell is probably soiled. To avoid measuring
errors, clean the cell thoroughly (see chapter 7.1.2
"Cleaning the measuring cell", page 49).
7.2.4.1 Electrostatic charging of the measuring cell
When the mV signal remains extremely stable during
the titration process and you are in doubt if the Mütek™
PCD-06 receives a signal from the measuring cell, test
the instrument functionality as follows:
Switch on the motor and rub your hand quickly up and
down on the outside of the cell. This causes the signal
to bounce. If no such reaction is observed although the
motor is running, there is probably an electronics failure.
In this case please contact the Service Department of
BTG Instruments or your local agent of BTG Instru-
ments .
7.2.5 Functional testing of the pH electrode
Before starting a test series, measure a buffer solution
by means of the pH electrode which should respond wit-
hin 10-30 seconds. If it does not, clean and re-calibrate
the electrode. If the fault persists, replace the pH elec-
trode.
The pH-electrode is a consumable goods.
Its life time is guaranteed approximately 6 months.
7.3 Proper handling of the pH electrode
The pH electrode must not fall dry. Therefore always put
on the protection cap, when not using the electrode.
Alternatively use a tiny beaker with 3M KCl solution for
parking position inbetween measurements.
Always fill up the protection cap with fresh 3M KCl solu-
tion when you’ve finished operation. This will regenerate
the electrode ever time after use and will prolong the life
time of the electrode. The pH electrode will consum the
KCl ions, therefore it is needed to always use fresh KCl
solution.
Be carefull when laying the pH electrode on a table, in
order not to break the diaphragm. It is recommend
always to insert the pH electrode into a tiny beaker with
3M KCl solution for parking position inbetween measu-
rements.
Always calibrate the pH electrode (see chapter 5.9.3
"pH Calibration (optional)", page 44) prior to your mea-
surements (at beginning of every working day with the
unit).
The buffer solutions supplied are meant as single use
solutions. In order to assure reproducible results always
use new/ stable buffer solutions.