Hach DR/850, Procedures Manual, Page: 448 / 460

448
5.
Measure 10 mL of
the orange solution into
another sample cell
(the blank).
6.
Add 0.5 mL of
cyclohexanone to the
remaining orange
solution in the first
sample cell (the
prepared sample).
Note: Use a plastic
squeezer. Rubber bulbs
may contaminate the
cyclohexanone.
7.
Tightly cap the cell.
Shake vigorously for 30
seconds (the prepared
sample).
Note: The sample will be
red-orange, brown or blue,
depending on the zinc
concentration.
8.
Press:
TIMER ENTER
A 3-minute reaction
period will begin.
Note: Steps 9-11 must be
completed within 10
minutes after the timer
beeps.
9.
Place the blank into
the cell holder. Tightly
cover the sample cell
with the instrument cap.
10.
Press:
ZERO
The cursor will move to
the right, then the
display will show:
0.00 mg/L Zn
Note: If Reagent Blank
Correction is on, the
display may flash “limit”.
See Section 1.
11.
Immediately place
the prepared sample into
the cell holder. Tightly
cover the sample cell
with the
instrument cap.
12.
Press:
READ
The cursor will move to
the right, then the result
in mg/L Zn will
be displayed.
Note: Standard Adjust may
be performed using a
prepared 0.50 mg/L
standard. See Section 1.
ZINC,
continued