Palintest DPD Nos. 1 Photometer Tablets. 250 tablet box. (Palintest Code AP011).
Suitable for the Palintest Pooltest Photometer Kit range
1 Rinse the test tube with the sample leaving a few drops of the sample in the tube.
2 Add and then crush, the DPD No 1 tablet in the few drops of the water sample
until the tablet is thoroughly crushed.
3 Add the 10ml test solution, mix and seal the tube with the cap.
4 Select Phot 7 on Photometer.
5 Take the Photometer reading in the usual manner – see Photometer instructions.
6 The result represents the free chlorine residual in milligrams per litre (mg/l).
Stop the test at this stage if only free chlorine determination is required.
7 If it is desired to measure combined or total chlorine residual continue the test on
the same test portion. Select the ‘Follow On’ from the screen options to continue the
8 If shock treatment chemicals are present in the pool, add one DPD Oxystop tablet,
crush and mix to dissolve. Stand for one minute before proceeding.
9 Add one DPD No 3 tablet, crush and mix to dissolve.
10 Stand for two minutes to allow full-colour development.
11 Take photometer reading in the usual manner.
12 The result represents the total chlorine residual as milligrams per litre(mg/l).
13 The combined chlorine residual is obtained by subtracting the free chlorine
the residual result from the total chlorine residual result:-
ie Combined Chlorine = Total Chlorine – Free Chlorine