38
Two-point Calibration
• Proceed as described above for one-point cali-
bration, using pH7.01 as the first point, but do
not quit calibration by pressing CAL at the end.
Note
The meter will automatically skip the buffer that was used
for the first calibration to prevent errors.
• After the first calibration point is confirmed,
immerse the pH electrode with the Potential
Matching Pin into the second buffer (e.g.
pH4.01) and stir gently
If you are not going to perform a three-point calibration, it
is recommendable to use pH4.01 buffer if you are going to
measure acid samples, or use pH10.01 buffer for alkaline
samples.
Note
The electrode should be submerged ap-
proximately 4 cm (1½”) in the solution.
The temperature probe should be located
as close as possible to the pH electrode.
• Select the 2
nd
buffer value on the
secondary display by pressing
or
(e.g. pH4.01).
• Only when the reading is stable the
probe indicator " " will stop flashing
(after about 30 seconds) and the
"CFM" indicator will blink.
• Press CFM to confirm the calibration; if the reading is
close to the selected buffer, the meter stores the reading,
adjusting the slope point and the secondary LCD will
display the expected third buffer value.
If the reading is not close to the se-
lected buffer, “WRONG “ will blink.
• Press CAL and the calibration process
is ended with the offset and the 1
st
slope of the meter calibrated.
