Hach DR2400 - Page 220

Chlorine, Total
Chlorine, Total
Page 2 of 4
ChlorineTot_TNT_Other_DPD_Eng_Ody.fm
Interferences
5. Touch Zero.
The display will show:
0.00 mg/L Cl
2
6. Remove the cap from
a Free Chlorine DPD
Test ‘N Tube™. Add
10 mL of sample to the
tube. (Fill the vial to the
top of the Hach label.)
This is the prepared
sample.
7. Cap and slowly
invert at least 10 times to
dissolve the powder. (Ten
inversions should take at
least 30 seconds. One
inversion equals turning
the vial upside down,
then returning it to an
upright position.)
8. Touch the timer icon.
Touch
OK.
A two-minute reaction
period will begin.
9. When the timer
beeps, wipe the outside
of the vial that contains
the prepared sample.
10. Place the sample in
the adapter.
11. Touch Read.
Results will appear in
mg/L Cl
2
.
Interfering Substance Interference Levels and Treatments
Acidity
Greater than 150 mg/L CaCO
3
. May not develop full color or color may fade instantly.
Neutralize to pH 6–7 with1 N Sodium Hydroxide. Determine amount to be added on separate
sample aliquot, then add the same amount to the sample being tested. Correct for volume addition
(see 3.1.3 Correcting for Volume Additions).
Alkalinity
Greater than 300 mg/L CaCO
3
. May not develop full color or color may fade instantly.
Neutralize to pH 6–7 with 1 N Sulfuric Acid. Determine amount to be added on separate sample
aliquot, then add the same amount to the sample being tested. Correct for volume addition
(see Section 3.1.3 Correcting for Volume Additions on page 29).
Bromine, Br
2
Interferes at all levels
Chlorine Dioxide, ClO
2
Interferes at all levels
Chloramines, organic May interfere
Zero
Read