Use of reference materials

The assessment of competence (of laboratories, inspection bodies, product certifiers, etc.) by independent third parties has spread to new fields of analysis or testing, to such an extent that we may well wonder whether the machine is getting out of control. Is the understanding of texts written at the end of the seventies for their first version transferable as it is today to personnel in the fields concerned? It would seem that this extension, coupled with generational turnover, could complicate the lives of companies (including laboratories). Has the good farming sense that guided the drafters of the first versions given way to a more technocratic approach or not? This is a debate that we won't go into in detail here.

With the opening of accreditation to laboratories operating in these "new" fields, such as agri-food analysis, petrochemical analysis, veterinary analysis and, more recently, medical analysis, the problem of linking measurement results to a coherent system of units, in order to be able to compare the results produced by laboratories, has evolved. Aspects that have long been foreseen in standards requirements are increasingly being encountered when laboratories or inspection bodies are being assessed. These include situations where traceability to the SI international system of units is not technically obvious, or where references are defined by means of a specific procedure, or are based on consensus "standards". These so-called "difficult" cases rely on the use of MR reference materials.

Although standards offer great flexibility in the management and control of reference materials, many questions arise for users preparing an initial assessment of competence. This flexibility is not so obvious to laboratories taking their first steps towards accreditation. So much so, in fact, that the simple question "how do I use reference materials? was asked at a standards committee meeting by one of the committee's expert members, who is also in charge of an accredited testing laboratory. It therefore seems useful to recall the possibilities offered by standards.