General description

(free chlorine, DPD) Method: colorimetric with color card and sliding comparator 0.10 - 0.20 - 0.30 - 0.60 - 1.0 - 1.5 mg/l Cl pH: 6.5 - 6.8 - 7.0 - 7.2 - 7.4 - 7.6 - 7.9 MQuant^®

Chlorine containing disinfectants are most widely used. They are applied particularly to disinfect drinking water and swimming pool water. Water in public and private swimming pools must be disinfecting to kill bacteria and viruses. Chlorine-containing preparations or even chlorine gas itself are usually used for this purpose.
This MQuant^® Chlorine and pH test (formally MColortest^®) measures chlorine and pH using the easy to use color card. The evaluation considers the untreated sample so even turbid and colored water samples can be analyzed without further preparation.

Method
In weakly acidic solution free chlorine reacts with diethyl-p-phenylendiamine (DPD) to form a red-violet dye. The pH determination takes place by means of chlorine-resistant phenol red indicator solution, which changes colour from yellow to red-violet in the pH range of 6.5 8.2.
The chlorine concentration and the pH are each determined semiquantitatively by allocating the color to a value on a reference scale.

This test is not suitable for seawater.