Thermo Scientific Orion Star LogR™ Meter User Guide
34
ISE Technique
ISE Calibration
The calibration standards should be prepared in the same ISE units as the desired
sample results. Start the calibration with the lowest concentration calibration
standard and work up to the highest concentration calibration standard. Any
reagents, such as ionic strength adjustors, should be added to samples and
standards as specified in the electrode user guide.
1. Prepare the electrode, standards and any other required solutions for use
according to the electrode user guide.
2. In the measurement mode, press
until the arrow icon points to the top
line, press
until the
ISE
icon is shown and the temperature reading and
compensation setting (the third line of the display) has updated (approximately 3
seconds). Press
to begin the calibration.
3. Rinse the electrode with distilled or deionized water, shake any excess water off,
blot it dry and place the electrode into the least concentrated standard.
4. Wait for
ISE
icon to stop flashing. 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 concentration value of
the standard. Once the standard value is set, press
until the decimal point
is in the correct location.
5. Press
to proceed to the next lowest calibration standard and repeat
steps 3 and 4, working from the lowest concentration standard to the highest
concentration standard, or press
to save and end the calibration.
6. The actual electrode slope, in mV per decade concentration, will be displayed in
the main field and
will be displayed in the lower field.
a. For a one point calibration, press
and
/
to edit the slope. To
change the sign of the slope to negative or positive, press
until none of
the digits are blinking and the arrow icon is blinking and press
to change
the sign of the slope. Press
to return to the measurement mode.