Hanna Instruments HI 3221 Instruction Manual page 17

• When the reading is stable and close to the selected buffer, the Confirm
function key is displayed.
• Press Confirm to confirm calibration.
• The calibrated value and the third expected buffer value will be dis-
played.
• After the second calibration point is confirmed, immerse the pH electrode
and the temperature probe approximately 3 cm (1¾") into a third buffer
solution and stir gently. The temperature probe should be close to the pH
electrode.
• If necessary, press the ARROW keys to select a different buffer value.
• The " " tag will blink on the LCD until the reading is stable.
• When the reading is stable and close to the selected buffer, the Confirm
function key is displayed.
• Press Confirm to confirm calibration.
Repeat this procedure with two additional pH buffers to encompass the entire
sample pH range.
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