Hach POCKET COLORIMETER II Instruction Manual page 42

Phosphonates,
6.
Insert the ultraviolet
lamp into the mixing bottle.
Turn the power supply on
and digest the sample for
10–15 minutes.
Phosphonates are
Note:
converted to orthophosphate
during digestion.
Caution: Wear UV safety
goggles while the lamp is on.
continued
7.
After digestion, turn the
power supply off and
remove the lamp.
Caution: Mixing bottle may
be hot if long digestion
periods are used.
1—42
8.
Fill a 10-mL sample cell
to the 10-mL mark with the
digested sample.
Cool the sample to
Note:
room temperature if it is hot
from digestion.