Paperboard Moisture Conditioning Standards and ISO 186 Batch Acceptance Sampling Protocols
Paperboard moisture verification demands ISO 186 random lot sampling and preconditioning under ISO 187 before ISO 287 gravimetric testing.
Random Increment Extraction
Statistical Selection
Systematic selection of small material portions at irregular intervals ensures that a representative sample is gathered from a large production lot. Using random increment extraction prevents the bias that occurs when a technician only takes samples from the start or end of a reel. The method relies on a random number generator or a shuffled list to determine the exact timing or location of each pick.
Lot Verification
Quality audits for bulk shipments of pulp or paper require a sample that accounts for the variability across the entire batch. Implementing random increment extraction provides a mathematically sound basis for accepting or rejecting thousands of tonnes based on a few kilograms of material. Each small portion is combined into a composite sample for laboratory testing.
This approach averages out the fluctuations caused by minor process upsets during the run. It is particularly useful for verifying moisture content or ash levels in large orders.
Implementation Limit
Physical access to the centre of a wound reel often makes this method difficult to apply to finished products. If the increments are not truly random, the statistical power of the test diminishes. Strict timing protocols maintain the integrity of the data.