Chlorine Dioxide; Measuring Hints - Hach Pocket Colorimeter II Instruction Manuals

Chlorine Dioxide

For water and wastewater
DPD Method*

Measuring Hints

• Chlorine dioxide samples cannot be stored, they must be analyzed immediately
after collection to minimize loss of chlorine dioxide.
• Do not use plastic sample containers or measurement apparatus.
• If the chlorine dioxide concentration exceeds the upper limit of the test (5.00 mg/L
ClO ), the color will not develop properly. The display will show overrange
2
(flashing 5.50) when the concentration is 5.50 or more.
If the reading is over 5.00, dilute the sample with high quality water that is
chlorine demand-free and repeat the test. Some loss of chlorine dioxide may occur
during dilution. Multiply the result by the appropriate dilution factor.
* Adapted from Standard Methods for Examination of Water and Wastewater.
** Procedure is equivalent to Standard Methods, 4500 ClO
(0.05 to 5.00 mg/L ClO
USEPA accepted for drinking water
D.
2
1—53
)
2
Method 10126
**