Hanna Instruments HI 3221 Instruction Manual page 12

Allow for the electrode to adjust and reading to stabilize (hourglass symbol
turns off).
On the pH screen are displayed:
• pH reading with the selected resolution.
• Temperature reading in the selected unit (ºC or ºF).
• Temperature compensation mode (MTC - manual, ATC - automatic).
While in MTC mode the
manually changed using ARROW keys.
• Electrode condition during the calibration day.
• The buffers used in last pH calibration (if feature is enabled in SETUP).
• Available function keys in accordance to the model.
In order to take more accurate pH measurements, make sure that the
instrument is calibrated (see page 15 for details).
It is recommended that the electrode is always kept wet and rinsed thoroughly
with the sample to be measured before use.
The pH reading is directly affected by temperature. For accurate pH
measurements, temperature must be taken into consideration. If the sample
temperature is different from the temperature at which the pH electrode
was kept, allow a few minutes to reach thermal equilibrium.
To use the instrument's Automatic Temperature Compensation feature, submerse
the temperature probe into the sample as close to the electrode as possible and
wait for a few seconds.
If manual temperature compensation (MTC) is desired, the temperature
probe must be disconnected from the instrument.
The display will show the default temperature of 25 ºC, the last measured
temperature reading, or the last set temperature, with the "MTC" indication.
The "MTC" indication and the symbol light up on the LCD to indicate that
the instrument is in MTC mode and the ARROW keys can be used to enter the
desired temperature value.
Note: When in MTC mode the user can press and hold an ARROW key, and
the instrument will start incrementing /decrementing the temperature
value. The instrument keeps measuring and the display is updated
periodically.
indicate that the temperature can be
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