10
The Cobra Calibration:
1. Switch on the meter.
2. Place the electrode into a 7pH buffer
solution (afterwards place the elec-
trode into a 4pH or a 10pH buffer solu-
tion for better accuracy).
3. Press “
CAL
” to enter pH calibration
mode. The icon “
CAL
” will appear on
the LCD screen for one second and then
pH value (4, 7 or 10) will be displayed
on the LCD screen.
4. If the probe or buffer display an error:
•
the buffer is incorrectly inserted;
•
the probe is damaged
•
the probe can not detect the buffer in
below voltage range.
The meter will exit calibration mode
automatically after 10
seconds. “
End
” will ap-
pear on the LCD screen
in one second and then
will go back to normal
status.
Acceptable voltage range of each point:
pH 4.00 : 97mV ... 250mV
pH 7.00 : - 60mV ... 60mV
pH 10.00 : - 250mV ... -97mV
5. If the probe recognizes the buffer:
If the probe successfully recognizes the
CAL ATC
F
O
