Hach DR/850, Procedures Manual, Page: 442 / 460

442
9.
Press:
TIMER
ENTER
A 3-minute reaction
period will begin.
10.
When the timer
beeps, cool solutions to
25 °C (until cells feel
cool) with running tap
water. Then dry the cells
with a soft cloth.
11.
Pipet 0.5 mL of
Hydroxylamine
Hydrochloride Solution
into each cell. Swirl
to mix.
12.
Pipet 2.0 mL of
4.5 N Sodium
Hydroxide Standard
Solution into each cell.
Cap and invert to mix.
13.
Add 10 mL of Ferric
Chloride Sulfuric Acid
Solution to each cell.
Cap and invert
to mix.
14.
Add 10 mL of
deionized water to each
cell. Cap and invert
to mix.
15.
The display will
show: 3:00 TIMER 2
Press:
ENTER
A 3-minute reaction
period will begin.
Note: After this three-
minute reaction period,
proceed immediately
through steps 16-19.
16.
When the timer
beeps, immediately
place the blank into the
cell holder. Tightly
cover the sample cell
with the instrument cap.
VOLATILE ACIDS,
continued