Hach DR/700 Procedures Manual page 725

PHOSPHORUS, REACTIVE,
4.
Fill a cell with
10 mL of sample (the
blank). Cap. Collect
at least 40 mL of
sample in a 50-mL
beaker.
Note: Run a reagent
blank for this test. Use
demineralized water in
place of the sample in
Step 4. Subtract this
result from all test
results run with this lot
of PhosVer.
2 minutes
7.
Wait two minutes.
5.
Fill a PhosVer 3
Phosphate AccuVac
Ampul with sample.
Note: Keep the tip
immersed while the
ampul fills completely.
8.
Place the blank in
the cell holder.
Note: In bright sunlight
it may be necessary to
close the cell
compartment cover.
81-51
continued
30 seconds
6.
Place an ampul
cap securely over the
tip of the ampul.
Shake the ampul for
approximately 30
seconds. Wipe off
any liquid and finger
prints.
Note: A blue color will
form if phosphate is
present.
Note: Accuracy is
unaffected by
undissolved powder.
9.
Press:
ZERO
The display will
count down to 0.
Then the display will
show 0.0 mg/l, and
the zero prompt will
turn off.