ONORM EN ISO 7393-2 : 2000

National foreword
0 Introduction
1 Scope and field of application
2 Definitions
3 Principle
4 Reagents
5 Apparatus
6 Procedure
7 Correction of interface due to the presence of
    oxidised manganese
Annex A Separate determinations of combined chlorine
         of the monochloramine type, combined chlorine
         of the dichloramine type and of combined
         chlorine in the form of nitrogen trichloride
Annex B Preparation of water free from oxidizing and
         reducing substances
Bibliography
Tables
1 Terms and synonyms in relation to actual
    compounds in the solution
2 Analytical parameters from interlaboratory
    analysis for free residual chlorine

Defines a procedure for the determination of free chlorine and total chlorine in water, readily applicable to field testing. Based on measurement of colour intensity by visual comparison of the colour with a standards scale that is regularly calibrated. Special methods are required for sea water and waters containing iodides and bromides.