The principle consists in treatment of a test portion with sufphuric acid solution under specified conditions, comparison of the colour developed with that of the same volume of an agreed colour standard. By agreement between the interested parties, the colour developed may be measured in Hazen units (platinum-cobalt scale).
WITHDRAWN
ISO/R 755:1968
WITHDRAWN
ISO 755-3:1981
95.99
Withdrawal of Standard
May 27, 2002