Gravimetric Standard
International reference protocols define standardized oven-drying procedures to determine the absolute moisture content of paper and board lots at the time of sampling. Compliance with ISO 287 moisture testing requires weighing paper samples before and after drying in an oven at one hundred five degrees Celsius until constant weight is reached. This test method establishes true moisture percentage, serving as the benchmark that calibrates inline electronic sensors.
Laboratory Method
Sampling procedures demand immediate airtight sealing of paper specimens in moisture-proof containers to prevent water exchange with ambient air before initial weighing. The laboratory protocol specifies heating test specimens in ventilated drying ovens until successive weighings separated by minimum time intervals show no further mass loss. Moisture content is calculated as the loss of mass expressed as a percentage of the initial sample mass.
Precise analytical balances measuring to zero point zero zero one grams maintain procedure accuracy. Non-paper components like synthetic coatings or laminates must be reported, as volatile additives alter true moisture loss calculations.
Lot Acceptance
Test results dictate commercial acceptance or rejection when paper shipments arrive outside agreed moisture specifications. Commercial contracts reference this standard to resolve financial disputes regarding dry fiber mass and total delivered roll weight. Reliable gravimetric verification underpins global paperboard trading terms.
