BS PD CEN/TR 16797-1:2015

BS PD CEN/TR 16797-1:2015 provides guidance on the statistical assessment of declared values with respect to therelease, emission and/or content of dangerous substances. This Technical Report provides statistically-basedcriteria for type-testing (TT), further-testing (FT) and where a product has been shown to be consistent withmeasured values for the release, emission or content that are significantly below the declared values, thepoint where no-further-testing (NFT) is permitted.A series of fundamental principles are defined in the present document and two statistical approaches aredefined. The first approach is to use assessment by variables and this approach requires the data to benormally or log-normally distributed. This approach is recommended as the default option. The alternativeapproach based on assessment by attributes is appropriate for data sets that are not normally or log-normallydistributed. The downside to this form of assessment is that more test data are needed for the same level ofreliability. The present document introduces these assessment procedures and CEN/TR 16797-2 providesmore detail and the statistical proof that they satisfy the principles defined in this document. With both of theseapproaches the minimum frequency of testing is a function of the distance between the mean value anddeclared value and the variability of the data set, i.e. the sample standard deviation.To reduce the costs of testing, production plants producing a similar product may share data, e.g. be groupingthe product into clusters for statistical assessment of declared values. Rules for the use of clusters are givenin CEN/TR 16797-2.CEN/TR 16797-2 also contains rules for identifying outliers within a data set and guidance on using tests otherthan the reference method for FT.A list of tasks for product technical committees is given in CEN/TR 16797-2 as is a model clause for includingin product standards and rules of applications that may be cited in the product standard or copied into productstandards.Cross References:CEN/TR 16797-2:201589/106/EECRegulation (EU) No 305/2011