ISO 3702:1976

Anhydrous hydrogen fluoride for industrial use — Determination of sulphur dioxide content — Iodometric method

Applicable to products having SO2 contents between 0.002 % (m/m) and 0.20 % (m/m). The principle consists in addition of a measured volume of iodine solution to a test portion. Back-titration of the excess iodine using a standard volumetric sodium thiosulphate solution and calculation of the SO2 content from the amount of iodine used.