Thermo Scientific Orion DUAL STAR User Manual page 52

Calibration and Measurement
ORP Calibration Hints
The millivolt reading of an ORP standard is dependent on the reference system,
reference material and filling solution of the ORP electrode and the temperature
of the ORP standard . The ORP electrode can be automatically calibrated to read
420 mV relative to the Standard Hydrogen Electrode (E
Thermo Scientific ORP standard (Cat . No . 967901 or Cat . No . 967961), Thermo
Scientific ORP electrode (Cat . No . 9678BNWP , 9778BNWP , 9180BNMD or
9179BNMD) and 4 M KCl filling solution (Cat . No . 900011) or 4 M KCl gel (in Cat .
No . 9179BNMD) are used . The raw mV reading of an electrode with the same
conditions is 220 mV at 25 °C .
The Thermo Scientific ORP standard is stable and will not change over time, so
it is an ideal standard for any ORP measurement system . The Orion DUAL STAR
meter offers a simple, automatic calibration to the E
when using Thermo Scientific ORP electrodes and standard . Visit
www .thermo .com/waterapps for ORP application notes that include a table of
ORP standard values at different temperatures .
• The measurement mode (displayed to the right of the measurement value)
determines the type of calibration that the meter will perform . Set the
measurement mode to ORP for the channel that will be calibrated . Refer to
the Setup Menu section for instructions on setting the measurement mode .
• Prepare and condition the ORP electrode according to the instructions in the
electrode user guide .
• Make sure that the ORP electrode, ATC probe and reference electrode (if
applicable) are connected to the meter inputs that correspond with the
channel that will be calibrated .
• The meter will automatically recognize the Thermo Scientific ORP standard,
Cat . No . 967901 or Cat . No . 967961, during an ORP calibration . Always use a
freshly prepared ORP standard for calibration . Allow the standard and samples
to come to the same temperature for precise measurements .

Thermo Scientific Orion DUAL STAR
) at 25 °C when the
H
value in the ORP mode
H
pH/ISE Meter User Guide
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