This International Standard specifies the following four test methods for the determination of the hygroscopic moisture content of test samples: Method 1 — Gravimetric method; Method 2 — Karl Fischer volumetric method; Method 3 — Karl Fischer coulometric method; Method 4 — Mass-loss method. Any of these methods is applicable wherever the analytical value of a chemical constituent is to be calculated to a dried sample basis in the following ore types. a) Processed ores containing metallic iron (direct reduced iron). b) Natural or processed ores in which the sulfur content is greater than 0,2 % (mass fraction). c) Natural or processed ores in which the combined water is greater than 2,5 % (mass fraction). Any of these methods is applicable to a concentration range of 0,05 % (mass fraction) to 4,5 % (mass fraction) hygroscopic moisture. NOTE 1 Where the reportable moisture content of a commercial consignment of ore is required, the procedure in ISO 3087 is used. NOTE 2 With natural or processed ores outside the field of application specified in a), b) or c), a determination of a constituent at any level of concentration may be conducted using any of these methods, or as specified in ISO 7764. NOTE 3 Alternatively, the loss or ignition content may be measured as an estimate of the combined water content.