ISO 638:2008 specifies an oven-drying method for the determination of the dry matter in paper, board and pulp.
The procedure is applicable to paper, board and pulp which does not contain any appreciable quantities of materials other than water that are volatile at the temperature of 105 °C ± 2 °C. It is used, for example, in the case of pulp, paper and board samples taken for chemical and physical tests in the laboratory, when a concurrent determination of dry matter content is required.
This method is not applicable to the determination of the dry matter content of slush pulp or to the determination of the saleable mass of pulp lots.