31
SECTION 3,
continued
8. When the reading has stabilized or been accepted, the
standard number will change to
3
. (To accept this calibration
after two points, press
EXIT
. Press
ENTER
to accept the
calibration or
EXIT
to cancel the calibration without saving it.)
9. Remove the probe from the second buffer and rinse with
deionized water. Place the probe in the third buffer.
10. Press
READ
. The temperature and pH values will be updated
until a stable reading is reached.
11. When the reading has stabilized or been accepted, the slope
value and the
Store
and
?
icons will appear.
12. To save the calibration and return to the reading mode, press
ENTER
. To exit the calibration without saving it and return to
the reading mode, press
EXIT
.
3.3.2
Performing a Manual Calibration
1. Prepare two or three pH buffers according to the electrode
instruction manual.
2. Turn the instrument on. From the pH Reading mode, press
CAL
. Functional keys will appear in the lower left display
area.
CAL
and
?
will appear in the upper display area, along
with
Standard
and
1
. The numeric keypad will become active.
3. Place the pH electrode in a buffer (starting with the lowest pH
makes it easy to keep track).
4. Enter the pH value of the buffer using the number keys and
press
ENTER
. A flashing underscore (
__)
indicates where the
next number will be placed.
5. The pH value entered will appear and the temperature and pH
values will be updated until a stable reading is reached.
6. When the reading has stabilized, the standard number will
change to
2. (
If measuring in the mV mode, press
ENTER
to
accept the reading and continue.)
7. Rinse the electrode and place it in the next buffer.