Hanna Instruments HI 4221 - Manual (Page 44)

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mV & Relative mV MEASURE mV & Relative mV MEASURE mV & Relative mV MEASURE mV & Relative mV MEASURE mV & Relative mV MEASUREMENT MENT MENT MENT MENTSSSSS
mV/ORP mV/ORP mV/ORP mV/ORP mV/ORP MEASUREMENTS MEASUREMENTS MEASUREMENTS MEASUREMENTS MEASUREMENTS
Oxidation-reduction potential (ORP) measurements provide the quantification of the oxidizing or reducing power of the
tested sample.
To correctly perform a redox measurement, the surface of the ORP electrode must be clean and smooth.
DIRECT MEASUREMENT
To measure the mV of a sample using the Direct reading mode:
• Press
and then to enter mV Measure mode
(for the selected channel – HI 4222 only).
• Select the Direct reading mode (see mV Setup for details, page 32).
• Submerge the tip of the ORP electrode (4 cm/1½”) into the
sample to be tested and allow a few seconds for the reading
to stabilize.
• The instrument will display the measured mV value on the LCD.
Note: If the reading is out of range, “-----” will be displayed
on the LCD.
DIRECT / AUTOHOLD MEASUREMENT
To measure mV of a sample using the Direct/AutoHold reading mode:
• Press
and then to select mV Measure mode
(for the selected channel – HI 4222 only).
• Select the Direct/AutoHold reading mode (see mV Setup for
details, page 32).
• Submerge the tip of the ORP electrode approximately 4
cm (1½”) into the sample to be tested and allow a few
seconds for the reading to stabilize.
• The measured mV 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 mV 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.