LaMotte Dissolved Oxygen Water Quality - Manual (Page 10)

EPA COMPLIANCE
To qualify as an EPA accepted test, and to achieve the greatest accuracy, the
Sodium Thiosulfate Solution, 0.025N (4169) must be standardized daily. This
procedure follows Standard Methods for the Examination of Water and
Wastewater. Numbers in ( ) are for LaMotte products. These products are not
included in this kit but can be ordered from LaMotte Company by using the
specified code number.
8
4.
5.
2.
3.
1.
6.
Add 2 drops
of Sulfuric
Acid, 5N
(8517WT).
Use a 10 mL graduated
cylinder (0416) to add
15 mL of Deionized
Water (5115) to the
titration tube (0608).
Use a Direct
Reading Titrator,
0-1 Range (1.0
mL capacity)
(0376) to add 2
mL of Potassium
Bi-iodate (7346).
Use the 0.1 g
spoon (0699) to
add 0.2 g
Potassium Iodide
Crystals (6809).
Fill another Direct
Reading Titrator
(0376) with Sodium
Thiosulfate Solution,
0.025N (4169).
Swirl to mix.
Solution will turn
yellowish brown.
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0