Thermo Fisher Scientific C101 Colorimeter - Manual (Page 27)

Measurement: Chlorine Dioxide
C103 Colorimeter
23
2.7 Chorine Dioxide (0 – 11.4 ppm ClO
2
)
• DPD method
1
for Chlorine Dioxide - applicable to water, treated
water, and wastewater.
Note: 1 Adapted from “Standard methods for the Examination of Water and
Wastewater.”
1. Switch the meter on by pressing the ON/OFF key. The display will
show [CLO2] momentarily before displaying [STbY] indicating it is in
stand-by mode, waiting for either blanking or measurement.
2. Select a clean and dry vial, un-screw the cap and fill with sample
water to the line on the vial. Replace the cap, ensuring it is screwed
on finger tight to the vial.
3. Ensure the outside of the vial is clean, dry and absent of any marks
or finger-prints. Gently push the vial fully into the sample well of the
instrument, whilst aligning the ▼ mark on the vial with the ▲ mark on
the meter.
4. Press the ZERO key to initiate blanking of the meter. The display will
show [ZERo] while blanking is taking place.
Note: The meter will store and use the last blanking (or zero) value, even if it
is turned off, or if the batteries are removed.
Blanking
Sample
ZERO
ppm
5. Remove the vial from the meter and add into it the content of one
Chlorine Dioxide (Glycine) Reagent Sachet.
6. Replace the cap, ensuring it is screwed on finger tight to the vial.
Swirl the vial repeatedly for approximately 20 seconds, until the
powder has dissolved.
Note: Do not shake or invert the vial as this may result in the loss of Chlorine
Dioxide.