The 2012 International Vocabulary of Metrology: “VIM”

Abstract

One of the most important events in the last decade for thefuture of measurement is without any doubt the thirdedition of the International Vocabulary of Metrology,commonly called ‘‘VIM’’ (from the French title ‘‘Vocab-ulaire International de Me´trologie’’) [1]. It was developedin Working Group 2 (WG 2) of the Joint Committee forGuides on Metrology (JCGM) that consists of:• BIPM, International Bureau for Weights and Measures,• IEC, International Electrotechnical Committee,• IFCC, International Federation for Clinical Chemistryand Laboratory Medicine,• ILAC, International Laboratory AccreditationCooperation,• ISO, International Organization for Standardization,• IUPAC, International Union for Pure and AppliedChemistry,• IUPAP, International Unionfor Pure and Applied Physics,• OIML, International Organization for Legal Metrology.The formal structure of the membership was intended toguarantee that the resulting ‘‘Guides for Metrology’’ VIMand GUM (guide to the expression of uncertainty in mea-surement) [2] would be formally examined, approved, andformally backed up by international organizations andtherefore be internationally representative. It was alsoexpected that the presence of international professionalassociations such as IEC, IFCC, IUPAC, and IUPAP wouldpromote its implementation on the worldwide scene.The first VIM sometimes called ‘‘VIM 1,’’ was releasedin 1984 [3]. The second edition, sometimes called ‘‘VIM2,’’ was published in 1993/1995 [4]. The VIM that is nowavailable is the third version, called ‘‘VIM 3’’. It wasreleased in 2008 and has been re-issued with editorialcorrections on 16 February 2012 [1].VIM 1 and VIM 2 were mainly conceived by physicistsand engineers for measurements in physics and engineer-ing. Chemical measurement was considered to some degreein VIM 2, thanks to the presence of an IFCC representativeand by the fact that clinical chemistry—possibly throughits active Clinical Chemistry Division in the IUPAC—hadalready made considerable progress in the introduction ofmetrological principles in clinical measurement. In general,the growth of more metrological insight in ‘‘measurement’’in chemistry evolved considerably in the period 1970–2010and is still in full development [5].A first feature of VIM 3 is the change of title: ‘‘Inter-national Vocabulary of Metrology—Basic and generalconcepts and associated terms’’ whereas the title of VIM 1and VIM 2 was very different: ‘‘International vocabulary ofbasic and general terms in metrology’’ (emphasis by me).Stressing that concepts are to be defined, and not terms, isone of the basic clarifications by VIM 3. Without com-monly defined concepts, there is no possibility of validlytranslating the term associated with this concept from onelanguage into a similarly understood term in another lan-guage. That had to be a justification in its own right for anysuccessor of VIM 2. Introducing this in VIM 3 requiredconsiderable study and discussions.A second feature of VIM 3 is the concept ‘‘measurementuncertainty’’ (entry 2.26 in [1]) [2]. That change of think-ing was formally initiated by the International Committee