This handbook provides practical guidance on sampling uncertainty estimation in theNordtest TR handbook format. The handbook is an extract of, and based on theprinciples, methods and text of the Eurachem Guide Estimation of measurementuncertainty arising from sampling. The Eurachem guide is more extensive and providesdetails on theory and additional examples. In 2019 Eurachem published a revisededition and therefore also the Nordtest handbook is revised.

The major changes in this second edition are:

• the possible use of an unbalanced design is mentioned in Section 6 to estimatesampling uncertainty more cost-effectively;• a detailed discussion in Section 7 on uncertainty contributions included andneglected using the experimental designs in this handbook;• introduction in Section 9.6 using log-transformed data and an uncertainty factor,FU, to handle expanded uncertainties of more than 30 %;• a recommended software, RANOVA (in Excel), to be used for ANOVAcalculations;• updates to definitions and references to reflect current.

The overall purpose of this handbook is to provide a set of tools for calculation andcontrol of the sampling uncertainty of the sampling procedure. It is the intention tomake these tools and the understanding of their use available outside the world ofanalytical chemistry, although the basic principles applied originate from analyticalchemistry. We hope that this is achieved but if not, please recall that statistics generallyseem to be more complicated than it actually is…