Hanna Instruments HI 99141, Instruction Manual, Page: 12 / 20

12
OPERA
TIONAL GUIDE
If using pH 4.01 or 10.01 (or pH 9.18 for NIST) buffer
the ”
SAVE ” message is displayed and meter returns to pH
measurement mode.
Two-point calibration
Proceed with steps 1 through 3 under single point calibra‑
tion using 7.01 (pH 6.86 for NIST) pH buffer first. Then
follow steps below:
The ”
pH 4.01 USE ” message is then displayed.
Place the probe in the second calibration buffer (pH 4.01
or 10.01, or, if using NIST, pH 4.01 or 9.18). When the
second buffer is accepted, the LCD will display “
SAVE ”
for 1 second and the meter will return to the normal
measurement mode.
If the buffer is not recognized or the slope is out of accepted
range ”
--- WRONG ” is displayed. Change the buffer, clean
the electrode or press any key to exit calibration.
It is always recommended to carry out a two‑point calibra‑
tion for better accuracy.
When the calibration procedure is completed, the
tag
is turned on together with the calibrated points.
To exit calibration and reset default values
After entering the calibration mode and before the first point
is accepted, it is possible to quit the procedure and return
to the last calibration data by pressing the button. The
LCD displays “
ESC “ for 1 second and the meter returns to
normal mode.
To reset the default values and clear a previous calibration,
press the
SET button after entering the calibration mode
and before the first point is accepted.
The LCD displays “
CLEAR “ for 1 second, the meter resets to
the default calibration and the tag with the calibrated
points on the LCD disappears.