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6. pH Calibration
Short press
to turn on the meter; rinse the probe in distilled
water, Shake off excess water
Pour certain amount of pH 7.00 and pH 4.00 buffer solution into the
corresponding calibration bottles (to about half volume of the bottle);
Long press
to enter calibration mode; Short press
to exit.
Insert the probe into pH 7.00 buffer solution, make a quick stir, and
hold still. When the reading is stabilized (
stays on the LCD screen), short press
to
complete 1
st
point calibration. After calibration is completed, the tester will return to
measurement mode. Icon
will appear at the bottom left of the LCD screen. indicating a
successful 1st point pH calibration.
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).
If necessary (target pH>8.00), 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).
Notes about Calibrationhe
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-pt
Option
A
1
st
pt: 7.00 pH
2
nd
pt: 4.00 pH or
1.68 pH
Option
A
1
st
pt: 6.86 pH
2
nd
pt: 4.01 pH or 1.68
pH
Range < 7.00 pH
Option
B
1
st
pt: 7.00 pH
2
nd
pt: 10.01 pH or
12.45 pH
Option
B
1
st
pt: 6.86 pH
2
nd
pt: 9.18 pH or
12.45 pH
Range >7.00 pH
3-pt
1
st
pt: 7.00 pH
2
nd
pt: 4.00 or 1.68 pH
3
rd
pt: 10.01 or 12.45 pH
1
st
pt: 6.86 pH
2
nd
pt: 4.01 or 1.68 pH
3
rd
pt: 9.18 pH or 12.45 pH
Range: 0 to 14.00
pH
