ISO International Standard

Contains also titrimetric methods for determination of the total acidity, the hexafluorosilicic acid content and the non-volatile acids content and a method for calculating the hydrogen fluoric content. Specifies the scope and the field of application of these methods and declares the principle of the procedures. This second edition results from the incorporation of Addendum in the first one. Cancels and replaces the first edition ISO 3139/1974.