3. pH Calibration
3.1. Before first use or unused for a long time, fill certain 3M KCl solution in the calibration bottle,
soak probe for at least 15 minutes. Pay attention that, soaking solution little higher that pH bulb
will be enough. Users can make this solution by themselves. Preparation: dissolve 25g KCl in 100
ml of pure water.
3.2. Rinse the probe in pure water and dry it.
3.3. Fill certain amount (about half volume of calibration bottle) of pH7.00 and
pH4.00 buffer solution in separate pH calibration bottles;
3.4. Long press to enter calibration mode; Short press to exit.
3.5. Dip the probe in pH7.00 buffer solution and stir gently, leave to Stabilize
(LCD displays as shown in the picture on the right). Short press to
complete 1-point calibration. The tester then returns to measurement mode and calibration icon
appears on the LCD.
3.6. For multi-point calibration (either 2 or 3 point), rinse the probe in clean water and repeat
step 3.5 using 4.01pH and/or 10.01pH calibration solutions. After completion of each point, the
calibration icons (for 4.01pH) and (for 10.01pH) will appear on the LCD near the
.
4. pH Measurement
Short press to turn on the tester. Rinse the probe in pure water and dry it. Dip the probe in
sample solution, stir gently, leave it to stabilize.
Get readings after LCD displays
.
5. Special Notes
5.1. Tester can perform 1~3points automatic calibration. But pH7.00 or pH6.86 buffer solution
must be used to make 1st point calibration. Then use other buffer solution to conduct 2nd or 3rd
point calibration. Tester will recognize 5 kinds of pH buffer solutions. Refer to the following chart:
Calibration
USA Series
NIST Series
Indication icon
Recommended
1-point
7.00 pH
6.86 pH
Accuracy ≥ 0.1pH
2-point
7.00 pH,
4.01 pH or 1.68pH
6.86 pH,
4.01 pH or 1.68pH
Range:
<
7.00pH
7.00 pH,
10.01pH or 12.45pH
6.86 pH,
9.18 pH or 12.45pH
Range:
>
7.00pH
3-point
7.00pH, 4.01 or 1.68pH,
10.01 or 12.45pH
6.86pH, 4.01 or 1.68pH,
9.18 or 12.45pH
Range: 0~14.00pH
Diagram - 2