Hach DR/700 Procedures Manual page 227

SULFATE,
continued
7.
Add the contents
of one SulfaVer 4
Sulfate Reagent
Powder Pillow to
each sample cell.
Cap and invert several
times to mix.
Note: A white turbidity
will develop if sulfate is
present.
Note: Accuracy is not
affected by undissolved
powder.
10.
Press: ZERO
The display will
count down to 0.
Then the display will
show the standards
concentration and the
zero prompt will turn
off.
5 minutes
8.
Wait 5 minutes.
Note: Allow cells to
stand undisturbed.
Note: Perform Steps 9-
12 within 5 minutes
after the 5-minute
waiting period.
11.
Place the
prepared sample in
the cell holder.
Note: In bright sunlight
it may be necessary to
close the cell
compartment cover.
45-55
9.
Place the prepared
standard into the cell
holder.
Note: In bright sunlight
it may be necessary to
close the cell
compartment cover.
Note: If the display is
blank, repeat Steps 2
and 3.
12.
Within 5
minutes after the 5-
minute period, press:
READ
The display will
count down to 0.
Then the display will
show the results in
mg/L sulfate (SO
Note: Clean the sample
cells with soap and a
brush.
2-
).
4