Hanna Instruments HI 3221 Instruction Manual page 19

ERROR SCREENS
Wrong buffer
The calibration cannot be confirmed.
The pH reading is not close to the selected buffer. Select another buffer using
the ARROW keys or change the buffer.
Electrode Dirty/Broken alternatively with Buffer Contaminated
The calibration cannot be confirmed.
The offset of the electrode is not in the accepted range. Check if the electrode
is broken or clean it following the Cleaning Procedure (see page 59). Check the
quality of the buffer. If necessary, change the buffer.
Wrong slope
The calibration cannot be confirmed.
The evaluated slope is less than the lowest accepted value (80% of default
slope).
The evaluated slope is more than the highest accepted value (110 % of default
slope).
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