BSI PD CEN/TR 16797-1:2015
$142.49
Construction products: Assessment of release of dangerous substances. Guidance on the statistical assessment of declared values – Principles and rules of application
| Published By | Publication Date | Number of Pages |
| BSI | 2015 | 28 |
This Technical Report provides guidance on the statistical assessment of declared values with respect to the release, emission and/or content of dangerous substances. This Technical Report provides statistically-based criteria for type-testing (TT), further-testing (FT) and where a product has been shown to be consistent with measured values for the release, emission or content that are significantly below the declared values, the point where no-further-testing (NFT) is permitted.
A series of fundamental principles are defined in the present document and two statistical approaches are defined. The first approach is to use assessment by variables and this approach requires the data to be normally or log-normally distributed. This approach is recommended as the default option. The alternative approach based on assessment by attributes is appropriate for data sets that are not normally or log-normally distributed. The downside to this form of assessment is that more test data are needed for the same level of reliability. The present document introduces these assessment procedures and CEN/TR 16797‑2 provides more detail and the statistical proof that they satisfy the principles defined in this document. With both of these approaches the minimum frequency of testing is a function of the distance between the mean value and declared 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 grouping the product into clusters for statistical assessment of declared values. Rules for the use of clusters are given in CEN/TR 16797‑2 .
CEN/TR 16797‑2 also contains rules for identifying outliers within a data set and guidance on using tests other than 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 including in product standards and rules of applications that may be cited in the product standard or copied into product standards.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 4 | Contents Page |
| 5 | European foreword |
| 6 | Introduction |
| 7 | 1 Scope 2 Declared values |
| 8 | 3 Other principles |
| 10 | 4 Uncertainty 5 Rules of application 5.1 Introduction to the rules of application |
| 12 | Figure 1 —Flowchart on the selection of the rule of application |
| 13 | 5.2 Rule of application based on assessment by variables 5.2.1 Principles of assessment by variables |
| 14 | Figure 2 — Normally distributed data |
| 15 | Figure 3 — Skewed distributed data |
| 16 | 5.2.2 Type-testing 5.2.3 Further-testing |
| 17 | Table 1 — Assessment by variables: Conformity criteria for TT |
| 18 | Table 2 — Assessment by variables: Minimum test frequency for FT 5.2.4 Use of existing data and sharing data |
| 19 | 5.2.5 Outliers 5.2.6 No-further-testing (NFT) Table 3 — Assessment by variables: Criterion for no-further-testing |
| 20 | 5.3 Rule of application for products where the test values are significantly below the declared value (gamma rule) |
| 21 | Table 4 — Conformity criteria for TT for assessment by the gamma rule for data that has a coefficient of variation not greater than 0,65, e.g. leaching test data Table 5 — Minimum test frequency for FT for testing by the gamma rule for data that has a coefficient of variation not greater than 0,65, e.g. leaching test data |
| 22 | 5.4 Rule of application based on assessment by attributes 5.4.1 Where assessment by attributes should be selected |
| 23 | 5.4.2 Type-testing Table 6 — Minimum frequency of testing when using assessment by attributes 5.4.3 Further-testing |
| 24 | 5.4.4 Use of existing data and sharing data 5.4.5 Outliers 5.4.6 No-further-testing |
| 25 | Table 7 — Criteria for no-further-testing |
| 26 | Bibliography |
