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Chart -4 Self-diagnostic information of pH measurement mode
Self-diagnostic
information
Description
Check up
buffer error
Wrong pH buffer solution or exceed
the recognition range of the meters
1.Check if the pH buffer solution is correct
2. Check if the connection between meter
and probe is good
3. Check if the probe is failed
no stable
Press
key when measuring
value is not stable.
Press
when
icon appears
electrode error
1.
The measuring value is not stable
for long time (≥3min)
2.
Electrode slope <75%
1.Check the probe bulb and make sure
there is no air bulb in it
2.Replace the pH probe with a new one
Note:
“electrode error” also includes the situation where electrodes get aged or worn out.
5.6
Sample measurement
5.6.1 Rinse pH probe in purified water, allow it to dry, and submerge it in tested solution. Stir the
solution briefly and allow it to stay in the tested solution until
icon appears on LCD and a
stable reading is reached. The reading is the pH value of tested solution. Diagram
–7 is the
calibration and measurement process of pH meter.
Diagram-7
3
r d
point
calibration
Submerge the
probe in pH4.00
solution, press
key when
icon appears.
Press
key to turn on
the meter
Press
Key to enter
calibration
mode
1st point calibration
completed, press
key to enter
into measurement
mode
Solution
Measurement
2
nd
point
calibration
1
st
point
calibration
Submerge the
probe in pH7.00
solution, press
key when
icon appears.
Submerge the
probe in pH10.01
solution, press
key when
icon appears.
2nd point calibration
completed, press
key to enter
into measurement
mode
3rd point calibration
completed, meter
auto. enters into
measurement mode
