International Vocabulary of Metrology

International Vocabulary of Metrology
Title	International Vocabulary of Metrology
Abbreviation	VIM
Status	Published
Version	3rd edition (2012)
Organization	BIPM, IEC, IFCC, ILAC, ISO, IUPAC, IUPAP, OIML
Related standards	ISO/IEC Guide 99, ISO/IEC 17025
Website	https://www.bipm.org/en/publications/guides/vim.html

International Vocabulary of Metrology. It is the definitive reference document for establishing a common language in the science of measurement. Published as ISO/IEC Guide 99, it provides standardized definitions for fundamental and general terms used in metrology across all fields of science, technology, and regulation. Its primary purpose is to ensure global consistency and clarity in the terminology of measurement, thereby facilitating international trade, scientific cooperation, and regulatory compliance.

Definition and purpose

The core definition establishes it as a guide to the basic and general concepts associated with measurement, along with the terms used to describe them. Its fundamental purpose is to promote global harmonization of measurement terminology, which is essential for the comparability of measurement results worldwide. This harmonization directly supports international standards like ISO/IEC 17025 for laboratory competence and underpins the mutual recognition arrangements coordinated by ILAC. By providing unambiguous definitions, it serves as a critical tool for scientists, engineers, regulators, and accreditation bodies to communicate precisely about measurement processes and their uncertainties.

Historical development

The first edition was published in 1984 under the title "International Vocabulary of Basic and General Terms in Metrology," often called the "VIM 1st edition." This foundational work was a collaboration between several key international organizations, including the Bureau International des Poids et Mesures (BIPM) and the International Organization for Standardization (ISO). A significantly revised second edition followed in 1993, which expanded the scope and refined many definitions. The current and most comprehensive third edition, officially titled "International vocabulary of metrology – Basic and general concepts and associated terms," was published in 2012 by a joint committee of eight organizations: BIPM, IEC, IFCC, ILAC, ISO, IUPAC, IUPAP, and OIML.

Structure and content

The document is systematically organized into a series of chapters that group related concepts. It begins with a general introduction to metrology before detailing terms related to measurable quantities and units. Subsequent chapters cover concepts of measurement, measuring instruments, and the properties of measuring devices. A critical and extensive section is dedicated to the concepts of measurement uncertainty, a cornerstone of modern metrology. The structure facilitates easy reference, with each term presented with its definition, notes for clarification, and often historical context or examples. The content is designed to be applicable to all disciplines, from chemistry and physics to medicine and engineering.

Key concepts and terms

Among its most pivotal defined concepts are "measurement uncertainty," which quantifies the doubt about a measurement result, and "metrological traceability," which links a measurement result to stated references, typically through an unbroken chain of comparisons to International System of Units (SI) standards. It rigorously defines types of "errors," distinguishing between random and systematic components. Other essential terms include "calibration," "measurement standard" (such as those maintained by National Institute of Standards and Technology or Physikalisch-Technische Bundesanstalt), "accuracy," "trueness," and "precision." The definitions clarify the relationships between these concepts, which were often conflated in older literature.

Impact and applications

Its impact is profound in fields requiring precise and comparable measurements. It is indispensable for implementing quality management systems like those based on ISO 9001 and for the accreditation of testing and calibration laboratories per ISO/IEC 17025. In regulatory environments, such as those governed by the European Medicines Agency or the U.S. Food and Drug Administration, its terminology ensures consistency in compliance assessments. It underpins international comparisons organized by the BIPM's Consultative Committees and is essential for the work of national metrology institutes like NIST and NPL. Its application ensures that a measurement made in Tokyo is understood identically in Berlin or Washington, D.C..

Related documents and standards

It is part of a family of essential metrological documents. The foundational SI Brochure, published by the BIPM, defines the modern International System of Units. ISO/IEC Guide 98 (the "GUM") provides the detailed methodology for evaluating and expressing measurement uncertainty. For laboratory operations, ISO/IEC 17025 specifies general requirements for competence. The JCGM (Joint Committee for Guides in Metrology) is the body responsible for maintaining and updating both this vocabulary and the GUM. Other related standards include those from the International Organization of Legal Metrology (OIML) and sector-specific guides from organizations like the International Federation of Clinical Chemistry (IFCC).

Category:Metrology Category:International standards Category:ISO standards