Hach DR/700 Procedures Manual page 611

NITROGEN, MONOCHLORAMINE,
7.
Mix by vigorously
adding 40-50 mL of
sample to the beaker
labeled free
ammonia. Add 40-50
mL of sample to the
beaker labeled
monochloramine.
Note: Hold the beaker
2-3 inches above the
receiving beaker to
create turbulence.
10.
Wait 15 minutes.
While waiting, wipe
fingerprints, liquids,
etc. from the cells.
8.
Promptly fill a
Monochloramine
AccuVac ampul from
each beaker.
Note: Keep tips
immersed while the
ampul fills.
Note: Label the bottom
of each ampul with
proper sample name.
11.
Place the cell
labeled blank into the
cell holder.
Note: In bright sunlight
it may be necessary to
close the cell
compartment cover.
61-55
continued
9.
Invert the ampuls
to dissolve the
powder.
Note: For proof of
accuracy test a 0.50
mg/L NH -N solution
3
(add to the free
ammonia beaker). See
Accuracy Check.
12.
Press:
ZERO
The display will
count down to 0.
Then the display will
show
0.00 mg/L
and the zero prompt
will turn off.