Hach AutoCAT 9000 - Page 102

Total Chlorine
Total Ch lo rine
Page 100
50081_Chlorine_Total_Back.fm
1. Turn the instrument on
if necessary and access the
Methods menu.
Press
2 to choose
Select Method.
2. Highlight
Total Cl2 - Back.
Press the
CHECK MARK
to validate.
3. Press 1 to select
Run method.
Note: This method utilizes the
28.2 mN iodine titrant. See
Software Setup for Titrant
Installation on page 38 to install
this titrant.
4. Measure 200 mL of
sample solution with a
250-mL graduated cylinder
and transfer to a 250-mL
beaker with the specified
magnetic stir bar.
Note: Use the provided stir bar
to minimize iodine loss.
5. Pipet 1.00 mL of
reductant (0.00564 N PAO
or sodium thiosulfate) and
swirl to mix.
Note: The amount of PAO
required will vary for different
concentrations of chlorine. The
recommended amount of 1.00
mL is sufficient for about
1 mg/L of total chlorine. For
higher concentrations, a larger
amount of PAO should be
added.
Note: For total chlorine
concentrations below 0.1 mg/L,
dispense 800 digits of
0.00564 N PAO with a Digital
Titrator. See Optional
Reagents and Optional
Apparatus on page 104.
6. Place the sample
onto the AutoCAT 9000
stirrer platform.
7. Verify User.
Press
1 to confirm.
Press the
CHECK MARK to
enter a new user.
Note: This screen will be
skipped if the User ID has been
disabled in the Configuration
menu. See Setting a User ID
on page 27.
8. To enter a new sample
ID, reductant concentration,
reductant volume, or sample
volume, highlight the
appropriate selection and
press the
CHECK MARK.
Press 1 to confirm the
values.
Note: If the sample has not
been fixed, this procedure
requires the addition of
reductant prior to analysis.
AutoCAT Titration Method Total Cl2 - Back
A t CAT Tit ti M th d T t l Cl2 B k