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6. pH Calibration
6.1 Short press
to turn on the meter; rinse the probe in pure water. Shake off excess water.
6.2 Pour buffer solutions into the corresponding calibration vials (to about half volume of the vials).
6.3 Long press
to enter calibration mode (screen turns green);
6.4 Insert the probe into pH 7.00 buffer solution, make a quick
stir, and hold still. When the reading is stabilized ( stays on
screen), short press
to finish 1st point calibration. Then the
tester returns to measurement mode, icon
will appear at the
bottom left, indicating a successful 1st point pH calibration.
6.5 To calibrate 2nd point, use 4.00 pH buffer and repeat Step 6.3 to
6.4 (Do NOT turn off the tester after you finish pH 7 calibration).
will display next to
, indicating a successful 2-point pH
calibration (low and middle points).
6.6 If necessary, calibrate 3rd point using 10.01 standard pH buffer and repeat Step 6.3 to 6.4,
will show up next to
and
, indicating a successful 3-point calibration (high, low, and middle
points).
6.7 Notes about Calibration
1) The 1st point calibration must be 7.00 pH. Perform the 2nd and 3rd point calibrations (4.00,
10.01, 1.68, or 12.45) immediately after the 1st point calibration is finished. Do NOT turn off the
meter before you calibrate 2nd or 3rd point. Otherwise, you will need to restart the calibration
process with 7.00 pH first.
2) The pH 4.00 and 7.00 buffer solutions poured into the calibration vials can be used for up
to 10 times as long as they are not contaminated and the bottles are capped when not in
use. pH 10.01 can only be used for up to 5 times as it will lose its accuracy much faster. After
that, replace the buffer solutions in the calibration vials with new ones to keep the accuracy.
Keeping the freshness and cleanliness of calibration buffers is essential for accurate pH
measurement.
3) The tester can perform 1 to 3 points of automatic calibration and can recognize 5 types of pH
standard solutions. For details, please refer to the following table:
Calibration
USA Series
NIST Series
Indication
icon
Recommended
1-point
7.00 pH
6.86 pH
Accuracy requirement
≥ 0.1 pH
2-point
Option A
1st pt: 7.00 pH
2nd pt: 4.00 pH
or 1.68 pH
Option A
1st pt: 6.86 pH
2nd pt: 4.01 pH or
1.68 pH
Range < 7.00 pH
Option B
1st pt: 7.00 pH
2nd pt: 10.01 pH
or 12.45 pH
Option B
1st pt: 6.86 pH
2nd pt: 9.18 pH or
12.45 pH
Range >7.00 pH
3-point
1st pt: 7.00 pH
2nd pt: 4.00 or 1.68 pH
3rd pt: 10.01 or 12.45 pH
1st pt: 6.86 pH
2nd pt: 4.01 or 1.68 pH
3rd pt: 9.18 pH or 12.45 pH
Range: 0 to 14.00 pH
