Low-level measurements – Hach-Lange ISECL18103 User Manual User Manual
Page 5
1. Connect the
probe to the
meter. Make sure
that the cable
locking nut is
securely
connected to the
meter. Turn the
meter on.
2. Prepare a
minimum of 25 mL
of the sample(s) in
beakers or
appropriate
containers. Add
the contents of
one Chloride ionic
strength
adjustment (ISA)
powder pillow per
25 mL to each
sample.
3. Rinse the
probe with
deionized water.
Blot dry with a lint-
free cloth.
4. Add a stir bar
and put the probe
in the sample. Do
not put the probe
on the bottom or
sides of the
container.
5. Put the beaker
on an
electromagnetic
stirrer and stir at a
moderate rate.
Check for air
bubbles and
remove them if
necessary.
6. Push Read.
The display will
show "Stabilizing"
and a progress
bar as the probe
stabilizes in the
sample. The
display will show
the lock icon when
the reading
stabilizes.
7. Repeat steps 2
- 6 for additional
measurements.
8. When
measurements
are done, store
the probe (refer to
on page 10).
Low-level measurements
Use the following techniques for measurements at low concentrations (<10 mg/L Cl
–
).
•
Clean the probe regularly as specified in
•
Soak the probe in the lowest concentration standard solution for up to 1 hour before
calibration and measurement.
•
Set the stability criteria to a low value (refer to
on page 7).
•
Stir the standards and samples at a slow and steady rate to prevent the formation of
a vortex.
•
Use a dilute ionic strength adjustor (ISA) solution for calibration and measurements:
1. Dissolve the contents of one ionic strength adjustor powder pillow in 50 mL of
deionized water.
2. Add 5 mL of this solution to every 25 mL of standard or sample that is used.
Note: The ionic strength adjuster can be omitted only when all of the following conditions are
true:
•
The sample does not contain interferences.
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