Ion concentration measurement
45
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Performing calibration
Calibration is necessary to measure ion concentration.
We recommend performing calibration once a day, before measurement.
According to the following procedure, perform calibration accurately. To prepare the
standard solution, refer to the instruction manual for the ion electrode.
Conditioning of the electrode is necessary when the electrode has not been used for a
long time. Refer to the table below to condition the electrode.
Conditioning of the electrode is necessary before ion concentration is measured. Refer
to the table below to condition the electrode.
Note
・
For performing calibration or measurement, replace the internal solution inside the outer
tube of the ion electrode before using the electrode.
・
Either channel 1 or channel 2 of the instrument can be used for ion concentration
measurement. However, calibration must be performed for each channel because each
channel has its own calibration data.
・
Prepare at least 100 mL of the standard solution for calibration. An insufficient volume may
cause the measured value to drift.
1. Clean the ion electrode with pure water (or
deionized water) and wipe it with filter paper
or tissue paper.
Do not directly touch the responsive membrane.
2. Open the internal solution filler port of the ion
electrode.
If calibration is performed with the port closed,
the internal solution does not flow and the
measurement value is not stabilized. Make sure
to keep the port open during calibration.
Ion
Conditioning solution
Immerse time
Cl
−
100 mg/L Cl
−
solution
Approx. 10 min
F
−
Pure water (or deionized water)
Approx. 10 min
NO
3
1 mol/L potassium nitrate solution
(100 g/L KNO
3
)
2 to 3 hours
K
+
0.1 mol/L potassium chloride solution
(7.5 g/L KCl)
Approx. 12 hours
Ca
2+
Tap water
Approx. 3 hours
NH
3
No conditioning
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