Instructions for the determination of chlorine (DPD)
Free, combined and total chlorine
CHECKIT
Disc
®
Chlor
Chlor
Chlor
Accuracy: ± 5 % full scale
Tablets
DPD No. 1 (R) - free chlorine
DPD No. 3 (R) - combined and total chlorine
DPD No. 4 (R) - total chlorine
Rapid dissolving DPD tablets (green printed foil = Type Rapid (R)
Free chlorine (DPD No. 1 (R)-tablet)
å Fill both cells to the 10 ml mark and ç place one cell in the
left-hand compartment of the comparator as a blank. ç Add
one DPD No. 1 (R)-tablet in the other cell, close it with a lid and
é swirl it until the tablet has dissolved. è Place this second cell
in the right-hand compartment of the comparator ê match the
two colour fields against north day light and read off the result
in mg/l free chlorine.
Total and combined chlorine
(with the addition of DPD tablet No. 3 (R)
Having completed the test for free chlorine, ë take the cell from
the right-hand compartment of the comparator, remove the lid
and add one DPD No. 3 (R)-tablet. í Replace the lid and swirl
the cell until the tablet is dissolved. ì Place the cell in the right-
hand compartment and î allow for 2 minutes reaction time.
Then compare the two colour fields against north daylight and
ï read off the result as total chlorine in mg/l.
Measurement Range Order Code
0 - 1.0
mg/l
0.1 - 2.0
mg/l
0 - 4.0
mg/l
Order Code (per 100 pcs)
14 60 10
14 60 40
14 60 20
51 13 10
51 12 90
51 15 70
1
2
3
4
5