Hach DR/850, Procedures Manual, Page: 251 / 460

251
Using AccuVac Ampuls
1.
Enter the stored
program number
for nitrite nitrogen
(NO
2
-
-N), AccuVac
Ampuls.
Press:
PRGM
The display will show:
PRGM ?
Note: For most accurate
results, perform a Reagent
Blank Correction using
deionized water (see
Section 1).
2.
Press:
62 ENTER
The display will show
mg/L, NO2-N and the
ZERO icon .
Note: For alternate forms
(NO
2
-
, NaNO
2
), press the
CONC key.
3.
Collect at least
40 mL of sample in a
50-mL beaker. Fill a
NitriVer 3 Nitrite
AccuVac Ampul with
the sample.
Note: Keep the tip
immersed while the ampul
fills completely.
4.
Quickly invert the
ampul several times to
mix. Wipe off any liquid
or fingerprints.
Note: Accuracy is not
affected by undissolved
powder.
5.
Press:
TIMER ENTER
A 15-minute reaction
period will begin.
Note: A pink color will
develop if nitrite is present.
6.
When the timer
beeps, fill a sample cell
with at least 10 mL of
sample (the blank).
7.
Place the blank into
the cell holder. Tightly
cover the sample cell
with the instrument cap.
8.
Press:
ZERO
The cursor will move to
the right, then the
display will show:
0.000 mg/L NO2-N
Note: If Reagent Blank
Correction is on, the
display may flash “limit.”
See Section 1.
NITRITE, Low Range,
continued