ISO 638:2008规定了用于测定纸张，纸板和纸浆中干物质的烘箱干燥方法。 该程序适用于在温度为105°C±2°C时不挥发的除水外的任何明显量的纸张，纸板和纸浆。例如，当需要同时测定干物质含量时，例如在实验室用于化学和物理测试的纸浆，纸和纸样品的情况下使用。 这种方法不适用于测定浆粕的干物质含量或纸浆批量的确定

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.