EN-23
Thermo Scientific Orion Star
™
and Star Plus Meter User Guide
Chapter VII
mV, Relative mV
and ORP Technique
All meters with pH measurement capability include a mV, relative mV and ORP
function . Measure the raw millivolt (mV) values of an electrode in the mV mode .
Calibrate the relative millivolt (RmV) values of a redox electrode for oxidation-
reduction potential (ORP) measurements in the relative mV/ORP mode .
Note:
The mV measurements are raw readings and cannot be calibrated.
Use the relative mV mode to calibrate mV measurements.
Relative mV and ORP Calibration
1 . Prepare the electrode according to the electrode user guide .
2 . In the measurement mode, press
until the arrow icon points to the top line,
press
until the
RmV
icon is shown and press
to begin the calibration .
3 . Rinse the electrode with distilled water and place it into the standard .
4 . Wait for the
RmV
icon to stop flashing . If the raw mV reading of the electrode
is 220 mV ± 60 mV, when the
RmV
icon stops flashing the meter will
automatically calculate and display the E
H
mV value for the electrode at the
measured temperature . If the raw mV reading of the electrode is outside of
the 220 mV ± 60 mV range, when the
RmV
icon stops flashing the meter will
display 000 .0 RmV . Press
until the first digit to be changed is flashing,
press
/
to change the value of the flashing digit and continue to change
the digits until the meter displays the millivolt value of the standard . To change
the value to negative or positive number, press
until none of the digits are
blinking and the arrow icon is blinking and then press
to change the sign
of the millivolt value .
5 . Press
to save and end the calibration . The millivolt offset will be displayed
and the meter will automatically proceed to the measurement mode .
Summary of Contents for Orion Star
Page 367: ......
