Hach DR/700 Procedures Manual page 86

BENZOTRIAZOLE AND TOLYLTRIAZOLE,
4.
Fill a square
mixing bottle with
25 mL of sample.
Note: For proof of
accuracy, use a 5.0 mg/L
benzotriazole standard
solution (preparation
given in Accuracy
Check) in place of the
sample.
Note: Sample
temperature should be
o
between 20 to 25 C
o
(68 to 70 F).
Note: If sample contains
nitrite or borax (sodium
borate), adjust the pH to
between 4 to 6 with 1 N
Sulfuric Acid.
5.
Add the contents
of one Triazole
Reagent Powder
Pillow (the prepared
sample). Swirl to
dissolve completely.
Note: If sample contains
more than 500 mg/L
hardness (as CaCO
add 10 drops of
Rochelle Salt Solution.
42-2
6.
Insert the
ultraviolet lamp into
the mixing bottle.
Note: UV safety goggles
should be worn while
the lamp is on.
),
3
continued