Thermo Fisher Scientific C101 Colorimeter - Manual (Page 13)

Measurement: Chlorine, Free & Total
C401/301/201Colorimeter
9
2.4 Chlorine, Free & Total (0 – 6ppm Cl
2
)
• DPD method
1
for Free Chlorine - applicable to water, treated water,
estuary water and seawater.
• DPD method
1
for Total Chlorine - applicable to water, treated
water, wastewater, estuary water and seawater.
The DPD Method is USEPA accepted for reporting drinking water
analyses (Free and Total Chlorine) and wastewater analyses
2 (Total
Chlorine only).
Note:
1
Adapted from “Standard methods for the Examination of Water and
Wastewater.”
Note: 2 Procedure is equivalent to USEPA method 330.5 for wastewater and
Standard Method 4500-Cl G for drinking water.
1. Switch the meter on by pressing the ON/OFF key.
2. Press the MODE key repeatedly until [CL – F] is displayed (for Free
Chlorine determination) or [CL – T] is displayed (for Total Chlorine
determination).
3. Press the READ/ENTER key to confirm the desired test parameter.
The meter will read [STbY] indicating it is in stand-by mode, waiting
for either blanking or measurement.
READ
ENTER
Free Chlorine test selection
4. 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.
5. 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.
6. 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