ISO 755-3:1981

Butan-1-ol for industrial use — Methods of test — Part 3: Sulphuric acid colour test

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).