Hach Lange APA 6000, Руководство по эксплуатации

Страница: 25 / 28

Section 5
Page 25
6200018bench.fm
Testing Samples for Total Hardness
5.3.1 Total Hardness Digital Titrator
®
Method
1. If a Digital Titrator
is used, fill a clean and
empty titration cartridge
with Reagent 3.
2. Insert a clean delivery
tube into the titration
cartridge. Attach the
cartridge to the titrator
body.
3. Turn the delivery knob
to eject a few drops of
Reagent 3. Reset the
counter to zero and wipe
the tip.
4. Refer to Table 10 to
choose the size of the
volumetric pipet,
depending on sample
concentration.
5. Using the volumetric
pipet, transfer the sample
volume from
Table 10 into
a clean 250-mL
Erlenmeyer flask.
6. Dilute to about the
100-mL mark with
deionized water.
7. Using a marked
dropper, add 1 mL of
Reagent 1. Swirl to mix.
8. Using a graduated
cylinder, add 8 mL of
Reagent 2. Swirl to mix.
Note: Prepare Reagent 2 by
mixing one bottle of Indicator
Powder into 1 L of Buffer
Solution. Reagent 2 can then
be kept for approximately
3 months.
9. Swirl the flask while
titrating with Reagent 3
from red to pure blue.
10. Record the number of
digits required. 11. Calculate the sample
concentration using the
equation below:
Refer to Table
10 on page 24.
FILL LIN
E
Sample Concentration mg/L as CaCO
3
( )
125 Digits Required Reagent 3 Titer M
( ) × ×
Sample Volume (mL)
---------------------------------------------------------------------------------------------------------------------- =