26
Set Reminder Period
Schedule the calibration reminder timing with this option (verify
Daily or Periodic is set for Calibration Reminder).
If a Daily reminder is desired, set the time of day you wish the
reminder to occur.
If a Periodic reminder is desired, schedule time in days, hours and/
or minutes after the last calibration for the reminder to occur.
To set the Reminder Period:
• Press
while in
pH Measure
mode.
• Press
.
• 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 edited.
• 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.
Clear Calibration
This feature deletes the pH electrode calibration for the attached
electrode and channel (
HI 5222
). A default meter calibration will
replace the actual electrode calibration until a new electrode
calibration is made.
To clear Calibration:
• Press
while in
pH Measure
mode.
• Press
.
• Use
or
to select the Calibration option.
• Press
and use
or
to highlight the
Clear Calibration option.
• Press
to clear calibration. A pop-up menu will be displayed asking for confirmation (when a
calibration is available).
• Press
to confirm or press
to escape without saving and return to the Calibration options.
55
• To return to normal Measure mode press
.
Note
: If the reading is out of range, “
----
” will be displayed on the LCD.
KNOWN ADDITION
To measure the concentration of a sample using the Known
Addition incremental method:
• Press
and then
to select ISE Measure mode
for the selected channel.
• Select the Known Addition method (see ISE Setup for details).
• Prior to starting a KA procedure, the ISE sensor must be
calibrated with a minimum of two standards containing ISA.
The slope of the electrode will be used in all calculations
involved in KA.
• If following an established procedure: Press
, Edit the
method variables and follow the procedure below.
• Press
to set the method parameters. Press
/
to select next/previous parameter to edit, then press
and use
or
to set the desired
parameter value. Press
to save the modified value
and then press
to exit method parameters edit
menu.
• If developing a procedure: Before attempting Known addition
analysis it is important to determine what sample volume,
standard concentration and standard volume will produce the
best results. As a general rule, the addition of standard
should change the mV value of the sample by 15 - 20 mV.
For a positively charged Ion (i.e. Sodium, Potassium, Calcium), the standard addition should increase the
mV. For a negatively charged Ion (i.e. Sulfide, Fluoride, Chloride), the standard addition should decrease
the mV. Start with a small trial. For example: Measure 50 mL of sample, add a magnetic stir bar, place
on a stirrer, add ISA (consult ISE manual) and place ISE electrode tip into the sample. Put instrument in
mV mode and record the observed mV. Using a micropipet, add a volume of the highest ISE standard
available (i.e. 0.1M or 1000 ppm). Start by adding 500 µL at a time (for example) Watch the change
in mV. When you have observed approximately a 15 mV change from the original sample. Calculate the
total volume added. Adjust sample and standard volumes proportionally to standard volumes that can be
measured with accuracy. Use volumetric pipettes for standard, ISA and sample addition.
• Press
: Edit the procedure variables to the volumes determined in the prior step.
