Hach Pocket Colorimeter II Instruction Manuals page 60

Chlorine Dioxide,
7.
Quickly invert the
ampule several times to mix.
Wait 30 seconds for any
undissolved powder to
settle. Accuracy is not
affected by undissolved
powder.
Note: A pink color will form
if chlorine dioxide is
present.
continued
8.
Within one minute after
filling the ampule, place it
into the cell holder. Cover
the ampule with the
instrument cap.
1—60
9.
Press
READ/ENTER
The display will show
"- - - -" followed by the
results in mg/L chlorine
dioxide.
.