Hanna Instruments HI 4521 User Manual
Page 28
28
Calibration Reminder
In order to have accurate readings, the instrument must be calibrated frecquently. Three options are available for
the calibration reminder: Daily, Periodic or Disabled.
To set the Calibration Reminder:
• Use
or
to select the Calibration option.
• Press
and use
or
to highlight the
Calibration Reminder option.
• Press
and use
or
to highlight the
desired option.
• Press
to confirm your selection or press
to
cancel operation.
Set Reminder Period
If choosing Daily or Periodic options for the Calibration Reminder, the Set Remind Period must be accessed in order to set
the time interval until next calibration. The time interval between two calibrations can be set up to 1 day / 1 year for
Daily / Periodic options.
Note: If Set Reminder Period parameter is accessed and the Calibration Reminder is disabled, a warning
message appears on the LCD informing the user that the reminder period can be set only if the Calibration
Reminder is set as Daily or Periodic.
To set the Reminder Period:
• Use
or
to select the
Calibration option.
• Press
and use
or
to highlight the
Set Reminder Period option.
• Press
and use
/
to select next /
previous entry to be edit.
• Press
and use
or
to set the desired
value, then press
to save the modified value.
• Press
to return to the Calibration options. If the Saving
Confirmation is enabled, press
to accept the modified
option,
to escape without saving or
to return to the editing mode. Otherwise, the modified
option is saved automatically.
89
Stage 3 - this is an off-line test.
To perform this test:
• Take the water sample from the previous test and increase its ionic strength for a pH measurement at
25 °C;
• Record the pH and round it to the nearest 0.1 pH;
• Look up the corresponding conducivity value measured in Stage 2 above;
• If the conductivity is lower than the conductivity from the below table, then the sample has met the USP
requirements. Otherwise, the water didn’t meet the USP requirements.
To access the USP menu:
• Select the
Direct / USP reading mode (see Conductivity Setup);
• Return to measure mode;
• Press (USP) and then select the desired USP stage.
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