Hach POCKET COLORIMETER II Instruction Manual page 24

Chlorine, Free and Total, LR,
4.
Press
ZERO/SCROLL
The display will show
"- - - -" then "0.00".
Remove the blank from the
cell holder.
5.
. Fill a second 10-mL cell
to the 10-mL line with
sample.
Do not use the same
Note:
sample cells for free and
total chlorine analysis
without thoroughly rinsing
the cells with sample
between free and total
tests.
1—24
continued
6.
Use the SwifTest™
Dispenser to add one
dispensation of DPD Free
Chlorine reagent or one
dispensation of DPD Total
Chlorine reagent to the
sample cell (the prepared
sample).