33
SECTION 3,
continued
5. Place the pH electrode in a buffer (starting with the lowest pH
makes it easy to keep track).
6. 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. It is not necessary that all four
places have a number entered in them.
7. The temperature and pH value will be updated until a stable
reading is reached.
8. When the reading has stabilized, the standard number will
change to
2.
If measuring in the mV mode, press
ENTER
to continue.
9. Rinse the electrode and place it in the next buffer.
10. Enter the pH value of the buffer using the number keys as
described above. Press
ENTER
.
11. When the reading has stabilized, the standard number will
change to
3
. Repeat steps 9–10 for other calibration buffers.
12. Press
EXIT.
The slope value and the
Store
and
?
icons will
appear. Verify the slope value is within the ranges specified in
the electrode manual.
13. 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
.
3.2.3
One-Point Calibration
The one-point calibration is used to adjust the calibration offset
and cannot be done unless a prior calibration using at least two
points is being used for measurements.
1. From the reading mode, press
CAL
.
Cal
,
1
,
?
, and
Standard
will be displayed.
2. Place the electrode in a pH calibration buffer.
3. Press
READ/ENTER
. The temperature and pH values will be
continuously updated until a stable reading is reached.
