Air ambiant — Détermination d'un indice de pollution gazeuse acide de l'air — Méthode titrimétrique avec indicateur ou détection potentiométrique du point final

Is applicable to mass concentrations of sulfur dioxide higher than 30 g/m3. The results obtained following this procedure depend on the amounts of acid and alkaline gaseous air pollutants which are likely to be determined under the specified sampling and analytical conditions.