Hach DR/850, Procedures Manual, Page: 343 / 460

343
9.
Pour 10 mL of
sample from the cell
labeled as “sample” into
a second clean, dry
sample cell. This is the
prepared sample.
10.
Add the contents of
one PhosVer 3
Phosphate Reagent
Powder Pillow for
10-mL samples to each
sample cell. Swirl
immediately to mix.
Note: A blue color will
form if phosphate is
present. Sample and blank
cells may develop color.
11.
The display will
show: 2:00 TIMER 2
Press:
ENTER
A two-minute reaction
period will begin.
Note: If sample is colder
than 15 °C, 4 minutes are
required for color
development.
12.
When the timer
beeps, place the blank
into the cell holder.
Tightly cover the sample
cell with the instrument
cap.
Note: Perform Steps 12-15
within three minutes after
the timer beeps.
13.
Press:
ZERO
The cursor will move to
the right, then the
display will show:
0.0 mg/L PO4
Note: If Reagent Blank
Correction is on, the
display may flash “limit”.
See Section 1.
14.
Place the prepared
sample into the cell
holder. Tightly cover the
sample cell with the
instrument cap.
15.
Press:
READ
The cursor will move to
the right, then the result
in mg/L phosphate will
be displayed. Multiply
this value by the
appropriate multiplier
from
Table 2 to obtain
the actual concentration
of phosphonates as
phosphate in the sample.
Note: Standard Adjust may
be performed using a
prepared standard (see
Standard Adjust in
Section 1).
16.
Results may be
expressed in terms of a
specific active
phosphonate by using
the appropriate
conversion factor and the
equation found in
Table
3 .
PHOSPHONATES,
continued