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RMO toolbox CIPM MRA

CIPM Mutual Recognition Arrangement (CIPM MRA)

The CIPM Mutual Recognition Arrangement (CIPM MRA) is an institutional and technical framework for National Metrology Institutes (NMIs) around the world to recognize each other’s measurement standards and calibration certificates. Its supporting data, representation of measurement capabilities, and quality infrastructure are rigorously validated by NMIs and other participants in the international measurement system.

Signatories of the CIPM MRA are the NMIs of Member States, the NMIs of Associate States and Economies, and certain international organizations invited by the CIPM. For some countries, authorities other than NMIs have signed the CIPM MRA.

A full list of CIPM MRA participating laboratories is available on the BIPM’s website:

In some countries, the NMIs do not cover all the metrology areas available to that country. Depending on the circumstances within individual countries, the relevant national authority (often the NMIs) can nominate other institutes in the country to cover specifically designated metrology areas. Those institutes are referred to as Designated Institutes (DIs), which have roles and rules in the CIPM MRA identical to those of the NMIs. The DIs are listed on the CIPM MRA participants webpage. To designate an institute, the relevant national authority, in most cases, the NMI has to follow a specific nomination process, which is detailed in the document CIPM-MRA-P-13 Participation in the CIPM MRA: National Metrology Institutes, Designated Institutes, International organizations.

The Joint Committee of the Regional Metrology Organizations and the BIPM (JCRB) is responsible for the coordination of CIPM MRA activities and data provided by the RMOs. The JCRB operates under the auspices of the CIPM and comprises representatives of the RMOs. The BIPM Director chairs the JCRB, supported by the JCRB Executive Secretary, and the BIPM maintains the Approved CMCs.

The outcomes of the CIPM MRA are the internationally recognized (peer-reviewed and approved) Calibration and Measurement Capabilities (CMCs) of the participating institutes. The CMCs are publicly available in the CIPM MRA database (KCDB).

CIPM MRA database (KCDB)

The three fundamental elements leading to approval of an institute's CMCs are:

  • participation by the institute in reviewed and approved scientific comparisons
  • operation by the institute of an appropriate and approved quality management system
  • international peer-review (regional and inter-regional) of claimed calibration and measurement capabilities.

The BIPM key comparison database (KCDB) publishes data from the CIPM MRA. It covers more than 1 500 scientific comparisons, around two-thirds of which are key comparisons (KC) and one-third are supplementary comparisons (SC). The KCDB publishes peer-reviewed and internationally recognised CMCs, which are supported by these comparisons. These CMCs cover the full set of metrological fields, which means the measurement capabilities that have realized mutual recognition at a global scale cover all scientific disciplines. A Help page and Getting started document are available on the website.

KCDB 2.0 - Online webinars
These online short courses from the BIPM are usually delivered in consultation with a particular RMO. They offer the skills to use the KCDB tools effectively for creation of CMCs, operation of the review process and piloting of comparisons.

KCDB 2.0 - Online webinars


RMO Secretariat access
RMO secretariats can access the KCDB by means of a specific user profile as an “RMO Secretary”. The RMO Secretary represents the RMO (the RMO President or any person having a strategic position within the RMO) but who does not write or review CMCs. The RMO Secretary is assigned an account by the KCDB Office on request. The RMO Secretary profile gives access to all TC Chair pages for all metrology areas, in a ‘read only’ mode for the RMO concerned.

RMO secretariats have dedicated user accounts, which give them access to KCDB statistics, for example on CMCs and comparisons. From the statistics menu, CMCs per area and/or RMO can be derived, evolution over time retrieved, and customized output collated. From this, RMO secretariats are also able to collate data on the number of their members’ CMC in specific metrology areas or numbers of participations in key and supplementary comparisons.

RMO secretariats can assign persistent CMC identifiers for their members/associate members that participate in the CIPM MRA by making use of a dedicated Application Programming Interface (API). These CMC identifiers are defined in the CIPM-MRA-G-13 guidelines and are specific in their nomenclature to each RMO. They can be used to pin-point a specific CMC, for example quality management documentation or for member laboratories when issuing calibration certificates.


The CIPM MRA processes, rules and roles are detailed in a set of three Policy documents and three Guidance documents:

Policy documents

  • CIPM-MRA-P-11 Overview and implementation of the CIPM MRA
  • CIPM-MRA-P-12 Coordination within the CIPM MRA: Consultative Committees, Regional Metrology Organizations, JCRB
  • CIPM-MRA-P-13 Participation in the CIPM MRA: National Metrology Institutes, Designated Institutes, International organizations

Guidance documents

  • CIPM-MRA-G-11 Measurement comparisons in the CIPM MRA: Guidelines for organizing, participating and reporting
  • CIPM-MRA-G-12 Quality management systems in the CIPM MRA: Guidelines for monitoring and reporting
  • CIPM-MRA-G-13 Calibration and measurement capabilities in the context of the CIPM MRA: Guidelines for their review, acceptance and maintenance

These documents are also available from: https://www.bipm.org/en/cipm-mra/cipm-mra-documents. The same page includes the text of the CIPM MRA.


A suite of brochures produced under the auspices of the BIPM Capacity Building and Knowledge Transfer Programme (CBKT) explain the whole CIPM MRA in plain language.

The suite of brochures covers the:

The JCRB directory, available on the BIPM website, displays the names of all RMO Technical Committee (TC) Chairs for the various metrology areas. Please note that for SIM, TCs are known as Metrology Working Groups (MWG).

RMO secretaries are asked to keep the information about their RMO in the JCRB directory up-to-date. They do this by informing the JCRB Executive Secretary whenever there are any changes.



M. Ibrahim Ahmed

International Liaison and Communication

M. Chingis Kuanbayev

International Liaison and Communication

Mme Stéphanie Maniguet

Chemistry Department and International Liaison and Communication