Chapter 4
|
Using the pH Channel
ORP Calibration Procedure (E
H
Units)
Orion Star A221 pH meters can perform a one point automatic ORP calibration to the E
H
value
(relative to the Standard Hydrogen Electrode, 420 mV at 25
°
C) when using the following items:
•
Thermo Scientific Orion ORP standard (Catalog Number 967901 or 967961)
•
Thermo Scientific Orion ORP electrode (Catalog Number 9678BNWP, 9778BNWP,
9180BNMD or 9179BNMD)
•
Thermo Scientific Orion 4 M KCl filling solution (Catalog Number 900011) or 4 M KCl gel
(in the 9179BNMD electrode)
Orion ORP standard is nonhazardous, stable and will not change over time, so it is an ideal
standard for any ORP measurement system. Always use fresh ORP standard. Prepare the
ORP electrode according to the instructions in the electrode manual. Connect all electrodes to
be used to the appropriate meter inputs.
Make sure the meter measurement mode is set to ORP.
1.
Press the f1 (cal) key to start the calibration.
2.
Rinse the electrode and any other electrodes in use with distilled water, blot gently with a
lint-free tissue to remove excess water and place into the standard.
3.
When the electrode and standard are ready, press the f3 (start) key.
4.
Wait for the mV value on the meter to stabilize (indicated by the flashing stabilizing or
solid ready icon) and press the f2 (accept) key once the mV value is stable.
5.
The meter will display the calibration summary including the mV offset and export the data
to the calibration log. Press the f1 (meas) key to proceed to the measurement mode or
press the f2 (print) key to export the calibration data to a printer or computer.
40
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Orion Star A220 Series Portable Meter User Manual
Thermo Scientific
Summary of Contents for Orion Star A220 Series
Page 5: ......
