Hanna Instruments HI 254 - Manual (Page 11)

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• 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
“READY” tag will be displayed and the “CFM” tag will blink.
• Press CFM to confirm calibration.
• If the fifth calibration point is reached, the instrument
stores the calibration value and returns to normal mea-
surement mode, or else it goes to the next calibration point.
Note: • If the value measured by the instrument is not close to the
selected buffer, “WRONG” “
BUF
” and “WRONG” “ ” tags will
blink alternately. In this case, check if the correct buffer has been
used or regenerate the electrode by following the Cleaning Proce-
dure (see page 30). If necessary, change the buffer or the
electrode.
• If “WRONG”, “Buffer pH” tags and “Old” tag on the secondary LCD
are displayed blinking, an inconsistency between new and previous
(old) calibration is detected. Clear calibration parameters by
pressing SET/CLR and proceed with calibration from the current
calibration point (the instrument will keep all confirmed values
during current calibration).
• The “WRONG” tag and temperature value are displayed blinking
if temperature reading is out of the defined temperature range of
the buffer. Calibration cannot be confirmed in this situation.
• Press RANGE to toggle between pH buffer, buffer
number and temperature reading on the secondary
LCD during calibration.
Note: Calibration parameters are evaluated taking in consideration the new
values for the confirmed buffers in current calibration and the old
values, if existing, for the other buffers. To clear old calibration values,
press SET/CLR before exiting calibration.