Hach AutoCAT 9000, Instruction Manual

Page: 85 / 176

Chlorine Dioxide
Chlorine Dioxide
50081_Chlorine_ChlorineDioxide.fm
Page 83
9.
Add 1.0 mL of pH 7.0
Phosphate Buffer Solution.
Press the
CHECK MARK
to confirm.
Note: Phosphate buffer is
added to adjust the sample pH.
The precise amount added is
not crucial for the accuracy or
precision of the analysis.
10.
Use the measuring
spoon to add 1.0 g of
potassium iodide (KI).
Press the
CHECK MARK
to confirm.
Note: KI is added in excess.
The precise amount added is
not crucial for the accuracy or
precision of the analysis.
11.
The timer will start.
This allows a short period of
time for the reagents to mix
before starting the titration.
12.
Lower the electrode
head onto the beaker rim.
Press the
CHECK MARK
to confirm.
13.
The analysis parameters
that have been stored for the
current Sub-ID may be
edited at this time.
Highlight the appropriate
line and press the
CHECK MARK
to change one
of the analysis parameters or
press
1
to confirm.
Note: Any changes made will
become the new default
parameters for this method
Sub-ID.
Note: These Sub-ID
parameters can be edited here
as 'run-time' settings, or from
the Main Menu as described in
Section 3.5.
Note: This step will be skipped
if auto-scaling software is
enabled.
14.
The Start Timer
will start to allow the
electrode to stabilize before
data collection.
Once the electrode has
stabilized, the AutoCAT will
begin data acquisition and
plot the titration curve.
15.
The Zoom Range
Determination window will
display the titration curve.
Use the navigation buttons to
select and move the cursors
to define the range of data
points for analysis.
Note: Defining the range of
data points excludes
undesirable portions of the
titration curve from
the analysis.
16.
Select type of end point
determination.
Press
DEL
for Manual.
Note: Automatic determination
attempts to identify linear
segments without user input
and is
not recommended for
this method.