Hach DR/850, Procedures Manual, Page: 333 / 460

333
Method 8311
OZONE
(0 to 0.25 mg/L O
3
, 0 to 0.75 mg/L O
3
or 0 to 1.50 mg/L O
3
) For water
Indigo Method
(Using AccuVac Ampuls)
1.
Enter the stored
program number for
Ozone (O
3
) AccuVac
ampuls.
Press:
PRGM
The display will show:
PRGM ?
2.
Press:
72 ENTER
for low range ozone
Press:
73 ENTER
for mid range ozone
Press:
74 ENTER
for high range ozone.
The display will show
mg/L, O3 and the
ZERO icon .
3.
Gently collect at least
40 mL of sample in a
50-mL beaker.
Note: Samples must be
analyzed immediately and
cannot be preserved for
later analysis. See
Sampling and Storage
following these steps for
proper collection.
4.
Collect at least 40
mL of ozone-free water
(blank) in another
50-mL beaker.
Note: Ozone-free water
used for the blank may
be deionized water or
tap water.
5.
Fill one Indigo
Ozone Reagent AccuVac
Ampul with the sample
and one ampul with
the blank.
Note: Keep the tip
immersed while the
ampul fills.
6.
Quickly invert both
ampuls several times to
mix. Wipe off any liquid
or fingerprints.
Note: Part of the blue color
will be bleached if ozone is
present. (The sample will
be lighter than the blank.)
7.
Place the sample
AccuVac ampul into the
cell holder. Tightly
cover the ampul with the
instrument cap.
Note: Standardization for
this procedure is
intentionally reversed.
8.
Press:
ZERO
The cursor will move to
the right, then the
display will show:
0.00 mg/L O3