Hach DR/700 - Page 221

45-49
Method 8022
SODIUM CHROMATE (0 to 1,000 mg/L)
For water, wastewater and seawater
Direct Colorimetric Method
1. Install module
45.01
in a DR/700.
Note: If samples cannot
be analyzed
immediately, see
Sampling and Storage,
below.
2. Press: I/O
The display will show
450 nm
and module
45.01
3. After 2 seconds,
the display will show
a program number,
the concentration
units, decimal
position and the zero
prompt. If necessary,
press the
UP ARROW
key until the lower
display shows
program number
45.06.1
4. Fill a 25-mL cell
to the 25-mL line
with sample.
Note: For proof of
accuracy, use a
1000 mg/L Sodium
Chromate Standard
Solution (listed under
Optional Reagents) in
place of the sample.
Note: Filter turbid
samples using the
labware listed under
Optional Apparatus.
5. Add the contents
of one Neutralizing
Reagent Powder
Pillow. Cap and
invert to mix (the
prepared sample).
Note: The Neutralizing
Reagent Powder Pillow
is necessary only if the
sample is orange or
yellow-orange. If the
color is in doubt, add
the powder pillow
contents.
6. Fill a 25-mL cell
to the 25-mL
demineralized water
(the blank). Cap.