Hanna Instruments HI 23 Series Instruction Manual page 33

Offset Calibration
Note
Cell constant calibration
To obtain accurate readings, use the calibration solution in
the selected range and closer to the values to be mea-
sured.
• To perform the EC or TDS calibration en-
ter the calibration mode, by pressing CAL
and entering the password.
• After the correct password is entered,
the control actions stop and the pri-
mary LCD will display the first EC or
TDS calibration value, with the "CAL"
indicator blinking. The secondary LCD
displays the temperature.
If the wrong password is entered the system reverts back to
normal operation, displaying EC or TDS values.
• 0 is the default value for the 1
tion point. Dry the conductivity probe
and leave it in air.
• Only when the reading is stable the "CAL"
indicator will stop flashing (after about
30 seconds) and the "CFM" indicator
will start blinking.
• Press CFM to confirm the calibration point;
the primary LCD will display the second
expected buffer value.
If the zero calibration cannot be performed,
"ERROR" will blink.
• Select the solution value on
the primary display by press-
ing or if the selected
range has two possibilities
(e.g. 5.000 and 12.880
mS).
• Immerse the EC/TDS probe with the temperature sensor in
the selected solution. The level of solution must be higher
than the holes of the EC/TDS probe sleeve. Tap the EC/
TDS probe repeatedly on the bottom of the beaker and stir
to ensure that no air bubbles are trapped inside the sleeve.
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calibra-
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