Hach-Lange HQD - Sodium (Na+) Ion Selective Electrode ISENa - Manual (Page 4)

4 DOC272.53.80027
1. Connect the
electrode to the
meter.
2. In three
separate beakers or
appropriate
containers prepare
25-mL standard
solutions of 10, 100
and 1000 mg/L Na
+
or use appropriate
standards that
bracket your
application range as
the standard set.
3. Add the
contents of one
sodium ionic
strength adjustment
(ISA) powder pillow
to each standard.
4. Select
Calibrate. The
display will border
the standard value
that is to be read
from the standard
set.
5. Place the
electrode in the 10
mg/L Na
+ solution
(containing the ISA)
or the displayed
standard value on
the meter calibration
screen (bordered on
display). Add a stir
bar and place the
beaker on an
electromagnetic
stirrer and stir at a
moderate rate.
6. Press Read.
The display will
show
Stabilizing...and lock
on the value when
complete. The
display will highlight
the standard value
that has just been
read and proceed to
the next standard
value.
7. Rinse the probe
with ISA rinse
solution (refer to
ISA
rinse solution
preparation on
page 8
). Blot dry.
Place the probe in
the next order
higher standard
solution and repeat
steps 5 and 6 and
press Read for the
100 and 1000 mg/L
Na
+ standard
solutions or
appropriate
standards used.
8. When the
minimum number of
points are collected,
the display will show
Done. Continue
calibration with the
method specified
calibration
standards (up to the
maximum number
specified in the Na
+
method) until all
have been read or
select Done to
review the
calibration
summary.
9. The display will
show the calibration
summary. Select
Store to accept the
calibration and
return to the
measurement
mode. The
calibration is
recorded in the
electrode and the
data log.