Hanna Instruments HI 3221 Instruction Manual page 21

Use the ARROW keys to change the buffer value.
Press Accept to accept new value or ESC to exit mode.
Note: Custom buffer value can be adjusted within a ±1.00 pH window,
around the set value.
WORKING WITH MILI pH BUFFERS
HANNA millesimal pH buffers are ± .002 pH buffers formulated to correspond
to nominal pH values. (1.000, 2.000, 3.000, 4.010, 5.000, 6.000, 7.010,
8.000, 9.000, 10.010, 11.000, 12.000, 13.000 and 9 that fall between).
These buffers require the user to use the closest standard buffer and adjust it,
or to use custom buffers. With these buffers it is possible to closely bracket the
measurement range of interest and insure an accurate measurement.
The resolution of the meter must be set to 0.001 pH (see SETUP on page 31).
Eight buffers are stored in instrument for calibration.
If calibration is invoked using millesimal buffers, the calibration buffer can be
modified within a ±0.020 pH range in accordance with the label on the
calibration buffer.
Press Change to enter buffer adjust mode.
Use ARROW keys to change the buffer value.
Press Accept to accept new value or ESC to exit adjusting mode.
CLEAR CALIBRATION
Press Clear function key when displayed to clear previous calibrations.
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