Terry Orchard

Blackhill Drive

Milton Keynes

MK12 5TS

United Kingdom


Specification Setting: Setting Acceptance Criteria from Statistics of the Data

This article shows how Probabilistic Tolerance Intervals of the form, "We are 99% confident that 99% of the measurements will fall within the calculated tolerance limits" can be used to set acceptance limits using production data that are approximately Normally distributed. If the production measurements are concentrations of residual compounds that are present in very low concentrations, it may be appropriate to set acceptance limits by fitting a Poisson or an Exponential Distribution.