NF ISO 33405, X07-035 (05/2024)

ISO/Guide 35:2017 explains concepts and offers approaches regarding the following aspects of reference material production: - homogeneity assessment; - stability assessment and risk management associated with potential stability issues related to properties of interest; - the characterization and assignment of values for the properties of a reference material; - assessment of uncertainty for certified values; - establishing metrological traceability of certified property values. The guidelines given support the implementation of ISO 17034. Other approaches can also be used as long as the requirements of ISO 17034 are met. ISO/Guide 35:2017 gives brief guidance on the need to evaluate commutability (6.11), but does not provide any technical details on this subject. A short introduction to the characterization of qualitative properties (9.6 to 9.10) is provided with brief guidelines for sampling such materials for homogeneity testing (Clause 7). However, this document does not address statistical methods for the assessment of the homogeneity and stability of reference materials with respect to qualitative properties. This document also does not apply to quantities with several variables, such as spectral data.
(Automatic translation from French)