ISO 2496:2006 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.

1. Processed ores containing metallic iron (direct reduced iron).
2. Natural or processed ores in which the sulfur content is greater than 0,2 % (mass fraction).
3. 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.