Hach DR/850, Procedures Manual, Page: 85 / 460

85
CHLORAMINE, MONO, Low Range
(0–4.50 mg/L Cl
2
) Method 10171
Indophenol Method
*
For chlorinated drinking water and chlorinated wastewater
* Patent pending
1.
Enter the user
program number for
monochloramine.
Press:
PRGM
The display will show:
PRGM?
2.
Press:
110 ENTER
The display will show
mg/L Cl
2
then: ZERO
Note: For alternate forms,
press the
CONC
key.
3.
Fill the 10-mL/1-cm
cell to the 10-mL line
with sample.
Note: For the most
accurate results, determine
a reagent blank for each
new lot of reagent by
running the test using
deionized water instead of
sample.
4.
Place the cell into
the instrument. Tightly
cover the sample cell
with the instrument cap.
Note: Place the cell into
the cell holder as
illustrated. The cell’s tab
should be at the 2 o’clock
position. Make sure the
sample cell tab is
completely seated in the
cell holder slot.
5.
Press:
ZERO
The cursor will move to
the right, then the
display will show:
0.00 mg/L Cl
2
6.
Remove the cell
from the cell holder and
add the contents of one
pillow of Monochlor–F
to the sample. Cap and
shake the cell about
20 seconds to dissolve.
7.
Press:
TIMER ENTER
A 5-minute reaction
period will begin.
Note: The color
development time depends
on the sample temperature.
Refer to Table 3 for the
actual time required.
8.
After the timer
beeps, place the cell into
the instrument. Tightly
cover the sample cell
with the instrument cap.
Note: Place the cell into
the cell holder as
illustrated. The cell’s tab
should be at the 2-o’clock
position. Make sure the
sample cell tab is
completely seated in the
cell holder slot.
Tab
Slot
Tab
Slot