The International Organization of Legal Metrology ( - OIML), is an intergovernmental organisation that was created in 1955 to promote the global harmonisation of the legal metrology procedures that underpin and facilitate international trade.
Such harmonisation ensures that certification of measuring devices in one country is compatible with certification in another, thereby facilitating trade in the measuring devices and in products that rely on the measuring devices. Such products include weighing devices, taxi meters, speedometers, agricultural measuring devices such as cereal moisture meters, health related devices such as exhaust measurements and alcohol content of drinks.
Since its establishment, the OIML has developed a number of guidelines to assist its Members, particularly developing nations, to draw up appropriate legislation concerning metrology across all facets of society and guidelines on certification and calibration requirements of new products, particularly where such calibration has a legal impact such as in trade, health care and taxation.
The OIML works closely with other international organisations such as the International Bureau of Weights and Measures (BIPM) and International Organization for Standardization (ISO) to ensure compatibility between each organisation's work. The OIML has no legal authority to impose solutions on its Members, but its Recommendations are often used by Member States as part of their own national legislation.
, 64 countries had signed up as Member States and a further 63 as Corresponding (non-voting) Members including all the G20, EU and BRICS countries. Between them, the OIML Members cover 86 % of the world's population and 96 % of its economy.
The Headquarters of the OIML is located in Paris, France.
Definition of "legal metrology" The definition of "legal metrology" varies amongst jurisdictions, reflecting the extent to which metrology is bound into the jurisdiction's own legal and regulatory code. The OIML, in their publication International Vocabulary of Terms in Legal Metrology defined "legal metrology" as
In the glossary of their book Metrology - in short Howarth and Redgrave state that "legal metrology"
These two statements are held together by the words "regulatory", "accuracy" and "reliability". The word "regulatory" encompasses the "legal" aspects of the term – the role played by governments, national metrology institutes and standards organisations in creating a framework to ensure confidence in the accuracy and reliability of a measurement. This framework requires that the specified test and conformance operations are carried out, and that the certificates pertaining to these operations are filed in a manner that enables third parties to assess them should the need arise.
The OIML has identified four main activities that fulfil the purposes of legal metrology: Setting up of legal requirements, Control/conformity assessment of regulated products and regulated activities, Supervision of regulated products and of regulated activities, Providing the necessary infrastructure for correct measurements.
History The International Organization of Legal Metrology (OIML), an intergovernmental organisation, was established under a diplomatic treaty signed in Paris on 12 October 1955 to promote the global harmonisation of legal metrology procedures that underpin and facilitate international trade. Under French law, its principal body, the International Conference on Legal Metrology, is accorded diplomatic status.
The Convention that set up the OIML listed eight objectives behind its establishment. At the 2011 meeting in Prague of the International Committee of Legal Metrology (CIML), the OIML updated its mission to read:
At the same meeting, its objectives were then stated as follows: "To develop, in cooperation with our stakeholders, standards and related documents for use by legal metrology authorities and industry that when implemented will achieve the mission of the OIML". "To provide mutual recognition systems which reduce trade barriers and costs in a global market". "To represent the interests of the legal metrology community within international organisations and forums concerned with metrology, standardisation, testing, certification and accreditation". "To promote and facilitate the exchange of knowledge and competencies within the legal metrology community worldwide". "In co-operation with other metrology bodies, to raise awareness of the contribution that a sound legal metrology infrastructure can make to a modern economy". "To identify areas for the OIML to improve the effectiveness and efficiency of its work".
Structure The OIML, which has an annual operating budget of about two million euros that comes from Member subscriptionsSubscriptions currently range from €1 400 for Corresponding Members to €112 000 for Member States that have a population of over 100 million. is organised around a three-layer model:
The overall direction of the OIML is vested in the International Conference () which meets every four years. The Conference is attended by delegations from Member States and [non-voting] Corresponding Members of the Organisation.
The management of the OIML is vested in the International Committee ( - CIML). The Committee consists of one member from each Member State. These members normally have active official functions in legal metrology in their country. The Committee elects a non-salaried President for a six-year term of office from amongst its Members. The Committee meets annually under the chairmanship of its President.
Secretarial services, day-to-day running and financial management of the OIML are provided by the BIML (). The BIML is the OIML headquarters, located in the 9th Arrondissement of Paris and is headed by a salaried director who is, ex-officio, secretary to both the International Conference and the International Committee.
Senior postholders
CIML Presidents 1956-1962 M. Jacob (Belgium) 1962-1968 J. Stulla-Götz (Austria) 1968-1980 A. van Male (Netherlands) 1980-1994 K. Birkeland (Norway) 1994-2003 G. Faber (Netherlands) 2003-2005 M. Kochsiek (Germany - Acting President ) 2005-2011 A. Johnston (Canada) 2011-2017 P. Mason (United Kingdom) 2017-2023 R. Schwartz (Germany) 2023-date B. Mathew (Switzerland)
BIML Directors 1956-1973 M.V.D. Costamagna 1974-2001 B. Athané 2001-2010 J-F. Magaña 2011-2018 S. Patoray 2019-date A. Donnellan
Participation and membership The OIML has two categories of membership; "Member State" and "Corresponding Member". The Member State category is for countries or economies that are prepared to finance and actively participate in the work of the OIML and which have acceded to the OIML Convention.
The Corresponding Member category is for countries or economies that want to be informed of OIML activities, but cannot, or prefer not to, be a Member State. , a total of 64 states are Member States and 63 are Corresponding Members.
Member States
Corresponding Members
Work
Technical Committees The technical work of the OIML is carried out by Technical Committees (TC), each committee having responsibility for a different aspect of legal metrology. In some cases the Technical Committee is broken up into one or more Subcommittees (SC). Within each TC or SC the actual technical work is carried out by Project Groups led by conveners. TCs, SCs and Project Groups are led by volunteer experts from OIML Member States. there are 18 Technical Committees and 46 Subcommittees. The Technical Committees are:
TC 1 Terminology TC 2 Units of measurement TC 3 Metrological control (5 SCs) TC 4 Measurement standards and calibration and verification devices TC 5 General requirements for measuring instruments (2 SCs) TC 6 Prepackaged products TC 7 Measuring instruments for length and associated quantities (4 SCs) TC 8 Measurement of quantities of fluids (5 SCs) TC 9 Instruments for measuring mass and density (4 SCs) TC 10 Instruments for measuring pressure, force and associated quantities (5 SCs) TC 11 Instruments for measuring temperature and associated quantities (3 SCs) TC 12 Instruments for measuring electrical quantities TC 13 Measuring instruments for acoustics and vibration TC 14 Measuring instruments used for optics TC 15 Measuring instruments for ionizing radiations (2 SCs) TC 16 Instruments for measuring pollutants (4 SCs) TC 17 Instruments for physico-chemical measurements (8 SCs) TC 18 Medical measuring instruments (3 SCs)
Publications The OIML produces a number of publications, including:
Vocabularies (prefixed by the letter "V") that provide standardised terminology in the field of metrology. The OIML has produced two principal works:
International Vocabulary of Terms in Legal Metrology (VIML) which defines the terms used in legal metrology. The first edition of this work (1978) was the joint effort of seven international organisations - BIPM, IEC, IFCC, ISO, IUPAC, IUPAP and the OIML. Alphabetical list of terms defined in OIML Recommendations and Documents which defines the technical terms used in the various OIML Recommendations.
In addition, the OIML was a partner in the JCGMThe Joint Committee for Guides in Metrology (JCGM) has eight members: BIPM, IEC, IFCC, ISO, IUPAC, IUPAP, ILAC and the OIML. which produced the International vocabulary of metrology - Basic and general concepts and associated terms (VIM), a document published by the BIPM on behalf of the JCGM
Recommendations (prefixed by the letter "R") which are model regulations that establish the metrological characteristics required of certain measuring instruments and which specify methods and equipment for checking their conformity. Most of the Recommendations have a similar structure. The four main topics covered in the reports are metrological requirements, technical requirements, methods and equipment for testing and verifying conformity to requirements and test report format. Recommendations are written in such a manner that they can be adopted "as is" by countries that wish to do so, or countries can select those parts that they wish to include in their own legislation. 104 Recommendations have been published, usually in both English and French. Recommendations may be downloaded free of charge from the OIML website.
International Documents (prefixed by the letter "D"), which are informative in nature and intended to improve the work of the metrological services. 31 OIML Documents had been published in this series. Documents may be downloaded free of charge from the OIML website.
The OIML also published Basic Publications, Guides, Seminar Reports, Expert Reports and the OIML Bulletin.
OIML Certification System (OIML-CS)
The OIML-CS is a single Certification System comprising two Schemes: Scheme A and Scheme B. It was launched on 1 January 2018, replacing the OIML Basic Certificate System and the OIML Mutual Acceptance Arrangement (MAA).
The aim of the OIML-CS is to facilitate, accelerate and harmonise the work of national and regional bodies that are responsible for type evaluation and approval of measuring instruments subject to legal metrological control.
The objectives of the OIML-CS are
a) to promote the global harmonisation, uniform interpretation and implementation of legal metrological requirements for measuring instruments and/or modules,
b) to avoid unnecessary re-testing when obtaining national type evaluations and approvals, and to support the recognition of measuring instruments and/or modules under legal metrological control, while achieving and maintaining confidence in the results in support of facilitating the global trade of individual instruments, and