Hach DR/700 Procedures Manual page 313

POLYACRYLIC ACID,
10.
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.
STATISTICAL EVALUATION
A single operator repetitively tested samples of two laboratory prepared
solutions, using one DR/700, matched sample cells and two
representative lots of testing reagents. Testing 3.4 mg/L Acrysol LMW-
45, acid form, concentration samples the standard deviation was
±0.33 mg/L pAA.
Testing zero concentration samples, the limit of detection was 0.93 mg/L
pAA. The limit of detection was calculated as three times the standard
deviation when testing zero concentration samples (Adapted from
Analytical Chemistry, 1980, 52, 2242-2249).
continued
11.
Place the cell
labeled "sample" in
the cell holder.
Note: In bright sunlight,
it may be necessary to
close the cell
compartment cover.
50-63
12.
Press:
READ
The display will
count down to 0.
Then the display will
show the results in
mg/L polyacrylic acid
as Acrysol (acid
form, total solids
basis).
Note: If concentrations
of less than 1 mg/L are
being determined, see
the Interference section.
Note: For
concentrations above
the test range, dilute the
sample by an
appropriate factor and
repeat.