Hanna Instruments HI 4521 - Manual (Page 51)

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ISE CALIBRATION ISE CALIBRATION ISE CALIBRATION ISE CALIBRATION ISE CALIBRATION
(HI 4522 only) (HI 4522 only) (HI 4522 only) (HI 4522 only) (HI 4522 only)
For greatest accuracy, it is recommended to calibrate the instrument frequently. The instrument should also be recalibrated
whenever “No ISE Calibration” or “ISE Calibration Expired” message appears on the LCD, in the Reminder messages area.
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 display. This will make
the calibration a simple and error-free procedure.
PREPARATION
Pour small quantities of the standard 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.
Note: For accurate measurements, add the appropriate ISAB (Ionic Strength Adjustment Buffer) to the
calibration standards.
CALIBRATION PROCEDURE
Up to five-point calibration is possible, using five memorized standard solutions: 0.1, 1, 10, 100, 1000 ppm
and 5 custom solutions.
The ISE calibration and measurement can be performed with or without temperature compensation. If the
temperature compensation option is enabled, the isopotential point of the electrode must be set in ISE Setup in
order to perform correct concentration measurements.
Before calibrating, make sure that the appropriate Electrode Type has been selected in ISE Setup according to the
measured Ion/compound.
ISE Calibration screen description
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Reading Mode
This option allows the user to select between
Direct, Direct / AutoHold,
Direct/USP conductivity reading modes.
To set the reading mode:
• Use or to select the Reading Mode option.
• Press and use or to highlight the
desired option.
• Press to confirm your selection or press to
cancel operation.
Delete Profile
To delete one of the existing profiles:
• Use or to select the Profile option.
• Press and use or to highlight the
Delete Profile option.
• Press . A list with all customised profiles will appear on
the screen.
• Use or to select the desired profile and press
.
• Press to return to the previous menu.