3
Measurement (calibration)
1. Open the internal solution filler port.
2. If necessary, fill the electrode with new internal solution
until the solution level gets close to the internal solution
filler port.
3. Wash the electrode with pure water (or deionized water)
and wipe it with filter paper or tissue paper, prior to every
immersion into the standard or sample solution.
4. When there are air bubbles inside the responsive glass
membrane, stir the electrode lightly to remove bubbles.
5. Immerse the responsive glass membrane and liquid
junction in the sample solution completely.
Make sure that the surface of the internal solution inside
the electrode is higher than the surface of the sample
solution.
6. Rinse the electrode with the sample solution lightly to
remove bubbles. If bubbles remain on the electrode
surface, accurate measurement cannot be performed.
Note
Be sure to keep the internal solution filler port open during
measurement. If it is clogged with the solution, accurate
measurement cannot be performed. Wipe the solution with
cloth.
For calibration and measurement on pH meter, refer to the
instruction manual of pH meter.
If the measured value does not stabilize in measuring
the sample solution that contains hydrofluoric acid
As the sample solution that contains hydrofluoric acid
dissolves the responsive glass membrane, the
measured value may not stabilize immediately after the
measurement starts. Perform the following steps before
calibration in order to condition the electrode.
1. Immerse the electrode in the sample solution that
contains hydrofluoric acid until the indicated value
stabilizes. In general it takes about 3 to 10 minutes.
If more than 10 minutes is needed for stabilization, the
electrode must be cleaned.
2. Wash the responsive glass membrane with pure water
(or deionized water), and wipe it with filter paper or
tissue paper.
When more than 10 minutes is needed for stabilization
1. Remove the protective guard from the tip of the
electrode.
2. Wipe the responsive glass membrane with filter paper or
tissue paper moistened with a small amount of ethanol.
3. Immerse the responsive glass membrane in pure water
(or deionized water) for 2 to 3 hours.
As with the step 1., check the Stabilization of indicated
value again.
Note
Gently wipe the responsive glass membrane, taking care not to
damage it.
