Hach DR/850 Procedures Manual page 110

CHLORINE, TOTAL, Ultra-High Range, continued
5.
Press:
ZERO
The cursor will move to
the right, then the
display will show:
0.0 mg/L Cl
2
9.
Press:
READ
The cursor will move
to the right. The result in
mg/L chlorine (as Cl )
2
will be displayed.
6.
Remove the sample
cell from the cell holder
and add the contents of
one 25- mL DPD Total
Chlorine Reagent pillow
to the sample. Cap and
shake the sample cell
about 20 seconds to
dissolve.
Note: A pink color will
develop if chlorine is
present.
7.
Press:
TIMER ENTER
A 3-minute reaction
period will begin.
110
Tab
Slot
8.
Within 3 minutes
after the timer beeps,
place the sample cell
into the instrument.
Cover the sample cell
tightly with the
instrument cap.
Note: Place the cell into
the cell holder as
illustrated. The sample cell
tab should be at the
6-o'clock position and
completely seated in the
cell holder slot.