Hach DR/850, Procedures Manual, Page: 325 / 460

325
Method 8166
OXYGEN, DISSOLVED, High Range
(0 to 15.0 mg/L O
2
)
HRDO Method
For water and wastewater
1.
Enter the stored
program number
for dissolved oxygen,
high range.
Press:
PRGM
The display will show:
PRGM ?
2.
Press:
70 ENTER
The display will show
mg/L, O2 and the
ZERO icon.
3.
Fill a sample cell
(the blank) with at least
10 mL of sample. Fill a
blue ampul cap with
sample. Collect at least
40 mL of sample in a
50-mL beaker.
4.
Fill a High Range
Dissolved Oxygen
AccuVac Ampul
with sample.
Note: Keep the tip
immersed while the ampul
fills completely.
5.
Without inverting the
ampul, immediately
place the ampul cap that
has been filled with
sample securely over the
tip of the ampul. Shake
for about
30 seconds.
Note: Accuracy is not
affected by
undissolved powder.
Note: The cap prevents
contamination with
atmospheric oxygen.
6.
Press:
TIMER ENTER
A 2-minute reaction
period will begin.
Note: The two-minute
period allows oxygen
which was degassed during
aspiration to redissolve in
the sample and react.
7.
When the timer
beeps, shake the ampul
for 30 seconds.
8.
Place the blank into
the cell holder. Tightly
cover the sample cell
with the instrument cap.
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