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Chapter 4 | Calibration
4.2 Millivolt (mV) Offset
Adjustment
Oxidization Reduction Potential (ORP) or Redox is useful as
a relative indicator of the oxidizing or reducing nature of a
sample solution. The offset adjustment in the relative mV
(RmV) mode allows readings to be comparable to
reference. An offset of up to ±250 mV from the measured
raw mV value can be entered.
During the calibration, the meter will automatically
recognize when the Orion ORP standard (catalog number
967901 or 967961) is used. Once the reading is stable, the
meter will automatically display the value of the standard at
its measured temperature.
Alternative ORP standards can also be used to perform the
calibration. Once the reading is stable, manually enter the
value of the standard at its measured temperature.
Ensure the active measure mode is RmV.
Press the “Cal” key to start the calibration.
Rinse the ORP electrode and ATC probe and place
into the ORP standard.
Wait for the RmV value to stabilize.
a.
While the reading is stabilizing, the stopwatch
icon is shown and the reading flashes.
b.
When the reading is stable, the checkmark icon
is shown, and the reading is solid.
Once the reading is stable, accept or edit the
displayed ORP standard value:
a.
To accept the ORP standard value, press the
“Enter” key.
or
b.
To edit the ORP standard value, press the
or
key to change the value and then press
the “Enter” key to save the value.
iii.
Press the
key to increase by one
digit. Press and hold the
key to
quickly increase.
iv.
Press the
key to decrease by one
digit. Press and hold the
key to
quickly decrease.
The meter will display the calculated offset value and
then proceed to the main measure mode.
Note: Press the “Measure” key at any time to abort the
calibration and return to the main measure mode.
4.3 Temperature
Calibration
The thermistor sensor used for automatic temperature
compensation and measurement is both accurate and
stable, so frequent calibration is not required.
When an ATC probe is connected to the meter, use the
Temperature Calibration item within the Setup Menu to
perform a one-point offset calibration, up to
±
5.0 °C.
Use the
to select the displayed temperature units as degrees
Celsius or Fahrenheit.
Place the ATC probe into a solution with a stable
temperature and NIST traceable thermometer.
Press the “Menu” key to enter the Setup Menu.
Press the
or
key to scroll through the Setup
Menu list until the Temp. Calibration item is shown.
The temperature value will blink, indicating the
reading from the ATC probe is being measured.
Once the reading is stable, the value will stop
blinking and the checkmark icon will be shown.
Press the
or
key to adjust the temperature
value. The temperature offset value will be shown in
the 2
nd
field.
c.
Press the
key to increase the value by 0.1°.
Press and hold the
key to quickly increase.
d.
Press the
key to decrease the value by 0.1°.
Press and hold the
key to quickly decrease.
Press the “Enter” key to save the change.
Note: Press the “Measure” key at any time to abort the
calibration and return to the main measure mode.
Summary of Contents for Orion Lab Star PH111
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