10
3 cm
(1¼")
PROCEDURE
Calibration can be performed up to five-points.
For accurate measurements a three
-
point calibration is recommended.
The calibration buffer can be selected from the calibration buffer list that
includes custom buffers and the memorized standard buffers:
•
pH 1.68, 4.01, 6.86, 7.01, 9.18, 10.01
and
12.45
.
The custom buffers allow the user to calibrate in a buffer solution different
from a standard one. Up to two custom buffers can be set in SETUP menu
(see page 26). Each custom buffer value can be changed in a ±1.0 pH
window around the set value, during calibration, when it is selected; the
“
BUFFER pH
” tag will blink.
The instruments will automatically skip the buffer used during calibration
and the buffers which are in a ±0.2 pH window, around one of the
calibrated buffers.
All new calibrations will override existing stored calibration data in a
±0.2 pH window. The slopes adjacent to the new points will be
reevaluated.
FIVE-POINT CALIBRATION
• Submerse the pH electrode and the temperature
probe approximately 3 cm (1¼”) into a buffer
solution and stir gently. The temperature probe
should be close to the pH electrode.
• Press
CAL
. The “
CAL
” and “
BUF
” tags will
appear and the “
7.01
” buffer will be displayed
on the secondary LCD.
• If necessary, press the
ARROW
keys to select a different buffer value.
• The “ ” tag will blink on the LCD until the reading is stable.
• When the reading is stable and close to the selected
buffer, the “
READY
” tag will be displayed and the
“
CFM
” tag will blink.
• Press
CFM
to confirm calibration.
39
TROUBLESHOOTING GUIDE
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