Loppukerros

Loppukerros is a Finnish term used in measurement science and numerical analysis to denote the remaining discrepancy after a procedure has converged. It represents a final component of total uncertainty that captures error sources not explained by the primary model or calibration equation. Loppukerros can arise from model misspecification, unmodeled dynamics, instrument nonlinearity, or finite-precision arithmetic.

In calibration and data fitting, loppukerros refers to the difference between observed values and true values after the main fitting or calibration step. It is typically estimated alongside other uncertainty components and residuals, and may be analyzed to assess model adequacy. Reducing loppukerros involves refining the model, improving data quality, expanding the measurement protocol, or using higher-precision computation.

The term is common in Finnish-language texts on metrology, statistics, and numerical methods. In English-language equivalents, the concept is often described as residual error, final residual, or unmodeled error, though usage can vary by field. Overall, loppukerros serves as a useful label for the portion of error that persists after standard analytical or experimental procedures have been applied.