The International Vocabulary of Metrology (VIM) is a reference document that establishes internationally agreed-upon definitions for the fundamental concepts used in measurement science. Published by the Joint Committee for Guides in Metrology, the VIM provides a common language for metrologists, engineers, scientists, calibration laboratories, and standards organizations worldwide.
Rather than prescribing how measurements should be made, the VIM defines terms such as measurement, measurand, accuracy, precision, measurement uncertainty, calibration, traceability, and error. By standardizing these definitions, the VIM helps ensure that measurement results and technical discussions are interpreted consistently across industries, laboratories, and national borders.
The VIM is particularly important because many commonly used measurement terms have meanings in metrology that differ from their everyday usage. For example, the VIM distinguishes between measurement error and measurement uncertainty, and it defines calibration as an operation that establishes a relationship between measured indications and reference values, rather than simply “adjusting” an instrument.
For anyone studying measurement, calibration, quality assurance, or standards, the VIM serves as the authoritative source for metrological terminology and forms the foundation for many international standards, including those related to laboratory accreditation and measurement traceability.