Hach DR/700 Procedures Manual page 534

NITRITE, HR,
4.
Fill a 10-mL
sample cell to the
10-mL line with
sample.
Note: A 25-mL sample
can be tested using
25-mL sample cells and
optional reagents.
Note: For proof of
accuracy, a 100 mg/L
nitrite standard solution
(preparation given in
the Accuracy Check)
can be used in place of
the sample.
7.
Fill a 10-mL cell
to the 10-mL line
with sample (the
blank).
continued
5.
Add the contents
of one NitriVer 2
Nitrite Reagent
Powder Pillow. Cap
and shake to dissolve
(the prepared
sample).
Note: A greenish-brown
color will develop if
nitrite is present.
8.
Place the blank in
the cell holder.
Note: In bright light
close the cell
compartment cover.
57-28
10 minutes
6.
Wait 10 minutes.
9.
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.