- 6 -
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 1
st
point pH calibration.
To calibrate 2
nd
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 3
rd
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
For the self-diagnosis information, please refer to the table below:
