Hanna Instruments HI 4521 - Manual (Page 47)

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Make sure the instrument has been calibrated before taking pH measurements.
DIRECT MEASUREMENT
To measure the pH of a sample using the Direct reading mode:
• Press and then to select pH Measure mode.
• Select the Direct reading mode (see pH Setup for details).
• Submerge the electrode tip and the temperature probe
approximately 4 cm (1½”) into the sample to be tested.
Allow time for the electrode to stabilize.
• The measured pH value will be displayed on the LCD, together
with a short GLP information or “Default Calibration” message
if no pH calibration was performed.
Note: If the reading is out of range, “-----” will be displayed on
the LCD.
DIRECT / AUTOHOLD MEASUREMENT
To measure pH of a sample using the Direct/AutoHold reading mode:
• Press and then to select pH Measure mode.
• Select the Direct/AutoHold reading mode (see pH Setup for
details).
• Submerge the electrode tip and the temperature probe
approximately 4 cm (1½”) into the sample to be tested.
Allow time for the electrode to stabilize.
• The measured pH value will be displayed on the LCD. If pressing
, the “AutoHold” indicator will start blinking on the
LCD until the stability criterion is reached. The pH value will be
frozen on the LCD, along with “AutoHold” indicator.
• To return to normal Measure mode press .
Note: If the reading is out of range, “-----” will be displayed on
the LCD.
p H M E A S U R E M E N T p H M E A S U R E M E N T p H M E A S U R E M E N T p H M E A S U R E M E N T p H M E A S U R E M E N T
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Temperature Unit
The user can choose from the
Celsius, Fahrenheit or Kelvin temperature
units.
To set the temperature unit:
• Use or to highlight the Temperature Unit
option.
• Press and then use or to select
Celsius, Fahrenheit or Kelvin degrees unit.
• Press to confirm your selection or press to
cancel operation.
Reference Temperature (only for Linear or Non-Linear temperature compensation)
To set the reference temperature:
• Use or to highlight the Reference Tempera-
ture option.
• Press and then use or to increase
/ decrease the value.
• Press to save or press to cancel operation.