Hanna Instruments HI 98150N - Manual (Page 13)

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• The calibrated value is then displayed on the primary LCD and the
secondary LCD will display the fifth expected buffer value.
• After the fourth calibration point is confirmed, submerse the pH
electrode and the temperature probe approximately 3 cm (1¼”) into
the fifth 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, “
CFM”
tag blinks.
• Press CFM to confirm calibration.
• The instrument stores the calibration values and
returns to normal measurement mode.
Note: For HI 98140 calibration proceed as in the FIVE-POINT CALIBRATION
above. After the third point is confirmed the instrument stores the
calibration value and returns to measurement mode.
FOUR, THREE or TWO-POINT CALIBRATION
• Proceed as described in FIVE-POINT CALIBRATION section.
• Press
CAL after the appropriate accepted calibration
point. The instruments will return to measurement
mode and will memorize the calibration data.
ONE-POINT CALIBRATION
Two SETUP selectable options are available for one-point calibration:
“
Pnt” and “OFFS”. See page 22 for Setup information using “1Pnt”
parameter.
If the “
Pnt” option is selected, the adjacent slopes will be recalculated
using the new calibration value.
If the “
OFFS” option is selected, an electrode offset correction is performed
keeping the existing slopes unchanged, but offsetting all by same value.
• Proceed as described in FIVE-POINT CALIBRATION section.
• Press
CAL after the first calibration point was confirmed. The
instruments will memorize the one-point calibration
data and will return to measurement mode.
Notes: • Press Range to toggle between pH buffer
and temperature reading during calibration.
• If the value measured by the instrument is not close to the
selected buffer, “ WRONG” “ ” and “WRONG” “ ” tags
will blink alternately. In this case check if the correct buffer
has been selected or used, or regenerate the electrode by
following the Cleaning Procedure (see page 39). If necessary,
change the buffer or the electrode.
• If the buffer temperature or the manual temperature exceeds
the temperature limits of the buffer, “ WRONG” “ ” tags
and temperature reading will blink.