Hach DR/700 Procedures Manual page 278

NITRATE, HR,
10.
Press:
ZERO
The display will
count down to 0.
Then the display will
show 0.0 mg/L and
the zero prompt will
turn off.
continued
11.
Place the
prepared sample in
the cell holder.
Note: In bright sunlight
it may be necessary to
close the cell
compartment cover.
50-28
12.
Press:
READ
The display will count
down to 0. Then the
display will show the
results in mg/L nitrate
as nitrogen.
Note: A reagent blank
must be determined for
each new lot of
NitraVer 5. Repeat
Steps 4 to 12, using
demineralized water as
the sample. Subtract
this value from each
result obtained with
each lot of reagent.
Note: To convert the
results to mg/L nitrate
-
(NO ), multiply by 4.4
3
Note: Rinse the sample
cell immediately after
use to remove all metal
particles.