Dryness Reference
International laboratory specifications govern the method for establishing the moisture content of paper, board, and pulps. The application of the iso 638 oven dry method ensures that all moisture measurements are aligned with a globally accepted drying temperature. This standard establishes the dry mass baseline for all chemical and physical pulp property evaluations.
Testing Sequence
Samples must be weighed immediately upon collection to prevent moisture exchange with the surrounding air. They are then placed in a ventilated oven maintained at a continuous temperature of one hundred and five degrees Celsius. Drying continues until successive weighings, spaced at least one hour apart, differ by less than one-tenth of a percent.
Under the iso 638 oven dry protocol, this stable weight represents the complete absence of unbound water within the fiber network.
Invoicing Utility
This protocol prevents financial discrepancies in international pulp trades by removing moisture fluctuations from the weight of shipments. Cellulose fibers are hygroscopic and their weight increases when they are stored in damp ports. By applying the iso 638 oven dry test to representative samples, buyers can calculate the correct dry mass of the delivered tonnage.
This ensures that disputes over water absorption during transit do not occur.
