NAVI F-52, Instruction Manual

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Chapter 16 Reference
16.3 Ion measurement
232 HORIBA
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Troubleshooting
Troubleshooting on calibration
Can calibration be per-
formed with the second
standard solutions that
has a difference concen-
tration?
1)Maintenance of electrode
2)Check of standard solutions
3)Check of supplies required for
measurement
Preparation before calibration(Refer to the
instruction manual which comes with each
electrode.)
Check point
1)Fill the reference electrode with internal liquid (replace internal
liquid if dirty), rinse it, and condition it.
2)Check the types and concentrations of standard solutions and
whether supporting base (supporting electrolyte) is included in
standard solutions.
3)Stirrer, thermostatic bath (required for high precision measure-
ment, recorder, rinse bottle containing deionized water, and
pipette (required for measurement by standard addition method.)
Is the electrode
sensitivity avail-
able?
1)Set the stirrer at a constant stirring speed (300 to 500 r.p.m).
2)Take care that the temperature of standard solutions does not
change during measurement.
3)Prevent air bubbles from gathering on the tip (responsive mem-
brane) of the electrode.
Check points in calibration
Add appropriate indication base electrolyte to standard solutions
Note: This action is not required for nitrate ion electrodes.
Is supporting base (elec-
trolyte) included in stan-
dard solution?
Does the internal liquid of
reference electrode bleed
out? Is the liquid junction
part of reference electrode
clogged?
Are the readings of standard
solutions stable?
Are they free from any noise
resulting form stirring?
1)Open the rubber stopper at the inlet for internal liquid
2)Clean the electrode and the liquid junction part so t hat a small
amount of internal solution bleeds out of the liquid junction part.
Action for electrode(1)
Calibration
Action for electrode(2)
The responsive membrane of the ion electrode might have dete-
riorated or might have been covered with a coating substance.
1)For solid membrane(except fluoride ion electrodes), polish it
with abrasive paper which comes with the electrode.
2) For fluoride ion electrodes and glass electrodes, wipe their
responsive membrane using gauze soaked with ethanol, or the
like and then rinse it with water.
3)For other electrodes, rinse them and then immerse them in a
conditioning solution.
Are the readings of standard
solutions stable? Are they
free from drift?
Does the tempera-
ture of standard
solution change?
The temperature may change due to the heat gener-
ated by the stirrer. Use a thermostatic bath or place a
thermal insulator on the stirrer.
Does the internal solution
of the reference electrode
excessively bleed out?
1) For the sleeve type liquid junction part, tighten it a little
strongly.
2)For the ceramic type liquid junction part, replace the reference
electrode.
Take actions (1) and (2) for the electrode. If the sensitivity cannot
be recovered, replace the electrode. Measure the difference in
electric potential (mV) between two standard solutions and then
determine whether this recovery has occurred or not.
(To the measurement)