Hach DR/700 Procedures Manual page 662

OXYGEN, DISSOLVED, SHR,
4.
Fill a blue ampul
cap with sample.
Then fill a cell with
10 mL of sample (the
blank). Collect at
least 40 mL of sample
in a 50-mL beaker.
2 minutes
7.
Wait 2 minutes.
Note: A two-minute
reaction period enables
oxygen, which was
degassed during
aspiration, to redissolve
and react.
5.
Fill a High Range
Dissolved Oxygen
AccuVac Ampul with
sample.
Note: Keep the tip
immersed while the
ampul fills completely.
30 seconds
8.
After the two
minute period, shake
the ampul for 30
seconds.
69-2
continued
30 seconds
6.
Without inverting
the ampul,
immediately place the
ampul cap that has
been filled with
sample securely over
the tip of the ampul.
Shake the ampul for
approximately 30
seconds.
Note: A small amount of
undissolved HRDO
Reagent does not affect
results.
Note: The cap prevents
contamination with
atmospheric oxygen.
9.
Place the blank in
the cell holder.
Note: In bright sunlight
it may be necessary to
close the cell
compartment cover.