Water quality - Determination of free chlorine and total chlorine - Part 2: Colorimetric method using N,N-diethyl-1,4-phenylenediamine for routine control purposes
This part of 7393 specifies a method for the determination of free chlorine and total chlorine in water, readily applicable to field testing; it is based on measurement of the colour with a scale of standards which is regularly calibrated. Sea water and waters containing bromides and iodides comprise a group for which special procedures are required. This method is applicable to concentrations, in terms of chlorine (Cl2), from 0,000 4 to 0,07 mmol/l (0,03 to 5 mg/l) total chlorine. For higher concentrations the test portion must be diluted. If the speed of operation and the compactness of the equipment are not overriding requirements, spectrometic measureme