ISO 4689-3:2004 specifies a combustion/infrared method, using a high-frequency induction furnace, for the determination of the sulfur content of iron ores. This method is applicable to sulfur contents between 0,002 % (mass fraction) and 0,25 % (mass fraction) in natural iron ores, iron ore concentrates and agglomerates, including sinter products. The method is not applicable to iron ores containing more than 1,0 % (mass fraction) of combined water. The apparatus, of which the metal filter is equipped with a heating device, can be applied to iron ores containing less than 3,0 % (mass fraction) of combined water.determination of the sulfur content of iron ores. This method is applicable to sulfur contents between 0,002 %(mass fraction) and 0,25 %(mass fraction) in natural iron ores, iron ore concentrates and agglomerates, including sinter products. The method is not applicable to iron ores containing more than (mass fraction) of combined water. The apparatus, of which the metal filter is equipped with a heating device, can be applied to iron ores containing less than (mass fraction) of combined water