10
It is recommended to calibrate the instrument frequently, especially if
high accuracy is required.
The pH range should be recalibrated:
• Whenever the pH electrode or temperature probe is replaced.
• At least once a week.
• After testing aggressive chemicals.
• When extreme accuracy is required.
PREPARATION
Pour a small quantity of buffer solution into clean beakers. For
accurate calibration use two beakers for each buffer solution, the first
one for rinsing the electrode and the second one for calibration.
PROCEDURE
In order to perform pH calibration:
• Make sure that the meter is in the pH mode (
HI 9125
only).
• Remove the protective cap and rinse the electrode with some of
the buffer solution to be used for the first calibration point.
There is a choice of 5 memorized buffers: 4.01, 6.86, 7.01, 9.18 and
10.01 pH.
TWO-POINT CALIBRATION
• Press the
CAL
key. The “
CAL
” and “
” indicators will be
displayed. The secondary LCD will display buffer “
7.01
”. If a
different calibration buffer is desired (e.g. “
6.86
”), use the
ARROW
keys to change the displayed value.
• Submerse the electrode approx. 3 cm (1¼”) into the solution,
place the temperature probe as close as possible to the electrode
and stir gently.
pppppH CALIBRATION
H CALIBRATION
H CALIBRATION
H CALIBRATION
H CALIBRATION
or