20
INW - TempHion Instruction Manual
• In
the
Ref pH
box for the second point, enter the temperature adjusted reference
pH as noted in the preparation section above.
• Click
second
Measure
button. (Note: measured temperature must be +/- 1
degree of fi rst measured temperature or calibration will not be accurate!)
• When readings have stabilized to your satisfaction, click the
OK
button in the
pop-up box.
— Applying Calibration Values—
• Observe
the
M
and
I
values in the right hand section of the calculator. These
should be between the
M
and
I
values shown in the chart in Appendix B2.
• Click
the
Apply
button to apply calibration values.
• The reference values, the computed M and I, and the sample temperature will be
transferred to the calibration fi elds.
• Click
OK
to save the values to the sensor.
— Verifying Calibration Values—
• Using the Real Time Monitor, take a few readings while the sensor is still in
the buffer. Be sure units are set to pH. Readings should be very close to your
selected buffer.
ISE Channel Calibration
Introduction to ISE Calibration
INW recommends using the “known addition method” for preparing calibration
solutions. Using this method, the sensor is placed in 100 mL of distilled or
de-ionized water. A small amount of standard is added to create a known
concentration. The fi rst point is measured. An additional amount of the same
standard is added to create a second known concentration. The second point is
measured.
INW recommends the calibration standards listed below. The following instructions
are based on using one of these standards. If you use different standards or prefer not
to use the known addition method, you must use some other method to determine the
concentration used for the fi rst and second point when calibrating.
Recommended Standards
Bromide
• 0.1 Molar NaBr (equates to 7990 ppm)
Chloride
• 0.1 Molar NaCl (equates to 3550 ppm)
• 100
ppm
• 1000
ppm
