Hach DR/850, Procedures Manual, Page: 300 / 460

300
ORGANIC CARBON, TOTAL, Mid Range,
continued
9.
Lower one unopened
ampule into each Acid
Digestion vial. When the
score mark on the
ampule is level with the
top of the Acid
Digestion vial, snap the
top off the ampule and
allow it to drop into the
Acid Digestion vial.
Note: Do not invert or tilt
the vial after inserting the
ampule to prevent the
Indicator Reagent from
mixing with the contents of
the acid digestion vial.
10.
Cap the vial
assemblies tightly and
place them in the
reactor for 2 hours at
103–105 °C.
11.
Carefully remove
the vial assemblies from
the reactor. Place them
in a test tube rack.
Allow the vials to cool
for
one hour for
accurate results.
12.
Insert the
COD/TNT Adapter into
the cell holder by
rotating the adapter
until it drops into place.
Then push down to fully
insert it.
Note:
For increased
performance, a diffuser
band covers the light path
holes on the adapter. Do
not remove the diffuser
band.
13.
Enter the stored
program number for
Mid Range TOC.
Press:
PRGM
The display will show:
PRGM?
14.
Press:
117 ENTER
The display will show
mg/L and the ZERO
icon.
15.
Wipe the reagent
blank vial assembly with
a damp towel, followed
by a dry one, to remove
fingerprints or other
marks.
Note: The liquid in the
reagent blank vial should be
dark blue.
16.
Place the reagent
blank vial assembly in
the adapter.
Push straight down on
the top of the vial until it
seats solidly in the
adapter.