ISO 4278:1977

Sodium fluoride for industrial use — Determination of carbonate content — Gravimetric method

Applicable to products having contents, expressed as Na2 CO3 , more than 0.02 % (m/m). Describes the release of the carbon dioxide from a test portion by acidification and heating. Entrainment of the carbon dioxide in a flow of air and absorption in weighed absorption tubes containing soda asbestos. Specifies the weighing of the absorption tubes to determine the quantity released.