Hach DR/850 Procedures Manual page 407

SULFATE,
continued
Using AccuVac Ampuls
Choose Desired
Program Accuracy
1.
A User-Entered
Calibration is necessary
to obtain the most
accurate results. See
User Calibration Section
at the back of this
procedure. Program 92
can be used for process
control or applications
where a high degree of
accuracy is not needed.
5.
Fill a SulfaVer 4
Sulfate AccuVac Ampul
with sample.
Note: Keep tip
immersed until the ampul
fills completely.
2.
Enter the stored
program number
-
for sulfate (SO )-
4
AccuVac Ampuls.
Press:
PRGM
The display will show:
PRGM ?
6.
Quickly invert the
ampul several times to
mix. Wipe off any liquid
or fingerprints.
Note: A white turbidity will
develop if sulfate is present.
Note: Accuracy is not
affected by undissolved
powder.
3.
Press:
92 ENTER
The display will show
mg/L, SO4 and the
ZERO icon.
7.
Press:
TIMER ENTER
A 5-minute reaction
period will begin.
Note: Allow the ampul to
stand undisturbed.
407
4.
Fill a sample cell with
at least 10 mL of sample
(the blank). Collect at
least 40 mL of sample in a
50-mL beaker.
Note: Filter highly turbid
or colored samples. Use
filtered sample in this
step and as the blank.
8.
After the timer
beeps, place the blank
into the cell holder.
Tightly cover the sample
cell with the instrument
cap.