JCGM - Joint Committee for Guides in Metrology


In 1997 the Joint Committee for Guides in Metrology (JCGM), chaired by the Director of the BIPM, was formed by the seven International Organizations that had prepared the original versions of the Guide to the expression of uncertainty in measurement (GUM) and the International vocabulary of basic and general terms in metrology (VIM). The Joint Committee took on this part of the work of the ISO Technical Advisory Group 4 (TAG 4), which had developed the GUM and the VIM.

The JCGM has taken over responsibility for these two documents from ISO TAG 4, who originally published them under the auspices of the International Bureau of Weights and Measures (BIPM), the International Electrotechnical Commission (IEC), the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), the International Organization for Standardization (ISO), the International Union of Pure and Applied Chemistry (IUPAC), the International Union of Pure and Applied Physics (IUPAP), and the International Organization of Legal Metrology (OIML).

In 2005, the International Laboratory Accreditation Cooperation (ILAC) officially joined the seven founding international organizations.

The JCGM has two Working Groups:

  • Working Group 1 (JCGM/WG 1) on the GUM has the task of promoting the use of the GUM and preparing Supplements to the GUM for broad application.
  • Working Group 2 (JCGM/WG 2) on the VIM has the task of revising the VIM and promoting its use.

The principles of the GUM are now used worldwide at all levels of the measurement chain, i.e. from NMIs to industry. In consequence, it would probably be counterproductive to produce a new version of the GUM at this time although the Group is aware that it could be improved. The JCGM-WG1 has thus decided to produce Supplements to the GUM to cover some topics of interest in more detail, whilst also directing them to groups of users with different levels of expertise. In addition, the Group is preparing an introductory document to promote the sound evaluation of measurement uncertainty through the use of the GUM. In these new documents, the concepts and notations are kept coherent with the GUM, with the maximum possible reference being made to the principles and concepts of the GUM.

The VIM vocabulary is meant to be a common reference for scientists and engineers — including physicists, chemists, medical scientists — as well as for both teachers and practitioners involved in planning or performing measurements, irrespective of the level of measurement uncertainty and irrespective of the field of application. It is also meant to be a reference for governmental and intergovernmental bodies, trade associations, accreditation bodies, regulators, and professional societies.

The tasks of the JCGM are:

  • to promote the use of the Guide to the Expression of Uncertainty in Measurement (known as the GUM);
  • to prepare supplemental guides for its broad application;
  • to revise and promote the use of the International Vocabulary of Basic and General Terms in Metrology (known as the VIM).


BIPM - Bureau International des Poids et Mesures ILAC - International Laboratory Accreditation Cooperation OIML - Organisation Internationale de Métrologie Légale IEC - International Electrotechnical Commission IFCC - International Federation of Clinical Chemistry and Laboratory Medicine ISO - International Organization for Standardization IUPAP - International Union of Pure and Applied Physics IUPAC - International Union of Pure and Applied Chemistry
Last modified: 2018-05-18