TM 5-6630-215-12
(4) Total Hardness Test - (0-500 mg/l).
(a) Fill the plastic measuring tube level full of test water
and pour it into the mixing bottle.
(b) Add 3 drops of buffer solution hardness 1 and swirl to
mix.
(c) Add 1 drop of Manver hardness indicator solution, hardness
2.
(d) Add titrant reagent hardness 3 dropwise (counting the num-
ber of drops) until the color changes from pink to blue.
Mix the
solution by swirling after each drop addition.
(e) The total hardness in mg/l is equal to 17.2 times the num-
ber of drops of titrant reagent hardness 3 added.
(5) Total Hardness Test - (500-9000 mg/l range).
(a) Dilute the test water by pipetting 1 ml (using 1 cc/l ml
dropper) of the test water into a 25 ml graduated cylinder and adding
24 ml of distilled water.
Stopper the graduated cylinder and invert
several times to mix.
(b) Fill the plastic measuring tube level full of diluted test
water and pour it into the mixing bottle.
(c) Add 3 drops of buffer solution hardness 1 and swirl to
mix.
(d) Add 1 drop of Manver hardness indicator solution, hardness
2.
(e) Add titrant reagent hardness 3 dropwise (counting the
number of drops) until the color changes from pink to blue.
Mix the
solution by swirling after each drop addition.
(f) The total hardness in mg/l is equal to 430 times the num-
ber of drops of titrant reagent hardness 3 added.
(6) Magnesium Hardness.
The magnesium hardness in mg/l is found
by subtracting the calcium hardness value (in mg/l) from the total
hardness value (in mg/l).
h.
Sulfate Test Kit - 0-3000 mg/l (fig. 2-19).
(1) Sulfate appears in natural waters in a wide range of con-
centrations.
Mine waters and industrial effluents frequently contain
large amounts of sulfate from pyrite oxidation and the use of sulfuric
acid.
2-75
