Hanna Instruments HI 3220 - Manual (Page 25)

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It is recommended to calibrate the instrument frequently, especially if high
accuracy is required.
The ISE range should be recalibrated:
• Whenever the ISE probe or ion charge is changed.
• At least once a day.
• After testing aggressive chemicals.
• When calibration alarm time out is expired- “CAL DUE” warning blinks (if
feature is enabled).
Follow instructions for the individual electrode.
Due to electrode conditioning time, the electrode must be kept immersed a few
seconds to stabilize. The user will be guided step by step during calibration
with easy to follow messages on the LCD. This will make the calibration a simple
and error-free procedure.
PROCEDURE
Select the proper ISE probe in SETUP menu (only for HI 3222) or select the
proper Ion Charge slope (see SETUP for details, page 31).
Note: If the ISE probe has not been previously calibrated (at least one point),
the “----” will be displayed.
Pour small quantities of the buffer solutions into clean beakers. If possible, use
plastic beakers to minimize any EMC interferences.
For accurate calibration and to minimize cross-contamination, use two beakers for
each standard solution. One for rinsing the electrode and one for calibration.
The HI 3221 instrument offers a choice of six standard solutions: 0.1, 1, 10,
100, 1000, 10000 ppm and calibration up to 2 points. The HI 3222 offers
additional ranges for other concentration units. These cover 5 decades of
concentration. The HI 3222 permits a 5 point calibration. It is advised to
bracket expected ion concentration with your standards. For fluoride electrode
the 2 ppm standard is also available (HI 3222 only).
Remove the protective cap from the ISE electrode.
IIIIISE SE SE SE SE CALIBRATION CALIBRATION CALIBRATION CALIBRATION CALIBRATION
(HI (HI (HI (HI (HI 3221 & 3221 & 3221 & 3221 & 3221 & HI HI HI HI HI 3222 3222 3222 3222 3222)))))