Hach DR/700 - Page 611

61-55
NITROGEN, MONOCHLORAMINE, continued
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.
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.
9. Invert the ampuls
to dissolve the
powder.
Note: For proof of
accuracy test a 0.50
mg/L NH
3
-N solution
(add to the free
ammonia beaker). See
Accuracy Check.
10. Wait 15 minutes.
While waiting, wipe
fingerprints, liquids,
etc. from the cells.
11. Place the cell
labeled blank into the
cell holder.
Note: In bright sunlight
it may be necessary to
close the cell
compartment cover.
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.