WARNING
TM 5-6630-215-12
Ferric chloride solution and Halazone tablets.
Keep away from children.
Not for internal
use.
(2) Chlorine Demand Test.
(a) Fill one of the jars to the 200 ml mark with the water to
be tested.
(b) Add one Halazone tablet to the jar. Cap the jar tightly
and shake until the Halazone tablet is completely dissolved.
Each
tablet is equivalent to 5 mg/l available chlorine.
(c) Wait 5 minutes.
(d) Use the color comparator (fig.
2-16) and conduct the Resi-
dual Chlorine Test (para 2-22l) to determine the residual chlorine in
the sample.
Subtract the residual chlorine value from 5 to obtain the
Chlorine Demand of the sample water.
(e) If the residual chlorine in step (d) is zero, fill one of
the jars to the 100 ml mark with the water to be tested.
(f) Repeat steps (b) and (c).
(g) Determine the residual chlorine in the sample and subtract
it from 10 to obtain the chlorine demand of the sample water.
(h) If the residual chlorine in step (g) is zero, fill one of
the test jars to the 200 ml mark with the water to be tested.
(i) Repeat step (b), but add 3 Halazone tablets.
(j) Repeat step (c).
(k) Determine the residual chlorine in the sample and subtract
it from 15 to obtain chlorine demand of the sample water.
(3) Coagulation Test.
(a) Fill each of the four jars to the 200 ml mark with the
water to be tested.
(b) Add 1 drop of ferric chloride solution to the first jar
(marked No.
1), 2 drops to the second, 3 drops to the third and 4
drops to the fourth test jar.
(c) Add one measuring spoonful (0.05 g) of pulverized lime-
stone to each of the jars.
Cap the jars and shake vigorously for 30
seconds.
2-85
