International Organization of Legal Metrology

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. as of 2022, 62 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.

The work of the OIML overlaps with the work of a number of other international organisations. In order to minimise the impact of this overlap and also to ensure that the work of the OIML and other organisations can intermesh with each other, the OIML and other organisations have exchanged memoranda of understanding (MoU) with each other. as of 2019 the MoU in existence were:
On 3 December 2008 the International Bureau of Weights and Measures (BIPM), the United Nations Industrial Development Organization (UNIDO) and the OIML signed a three way MoU whereby each would apply their own expertise in the best way possible to ensure the better implementation of capacity building activities in standards and conformity, as well as compliance with sanitary and phytosanitary (SPS) measures. An MoU was signed with the International Organization for Standardization (ISO) on 10 June 1966, which was revised on 9 December 2008 whereby both organisations would cooperate via joint technical committees where applicable. A number of OIML Recommendations that were at variance with certain ISO standards were withdrawn. A process to fast track OIML Recommendations into ISO standards was also agreed. Joint reports issued by both organisations could be downloaded from the OIML website as with any other OIML document. An MoU was signed with the International Electrotechnical Commission (IEC) on 13 October 2011 during the 46th CIML Meeting in Prague. Under the MoU, the two organisations agreed to keep each other informed of their activities, and where appropriate, to set up joint technical committees and issue joint recommendations. On 10 October 2018 at the 53rd CIML Meeting, held in Hamburg, Germany, a renewed MoU was signed by Mr. Frans Vreeswijk (General Secretary and CEO of the IEC) and Dr. Roman Schwartz (CIML President). An MoU was signed with the International Laboratory Accreditation Cooperation (ILAC) on 12 November 2006 whereby ILAC and OIML would cooperate in the use of the OIML Mutual Acceptance Arrangement (MAA) tool and both organisations would cooperate in the field of harmonisation of accreditation by ILAC full members and peer assessments organised by the BIML. On 28 October 2007, during the ILAC/IAF General Assembly in Sydney, the MoU was extended to include the International Accreditation Forum (IAF) whereby ILAC and the OIML would cooperate in the use of the OIML Mutual Acceptance Arrangement (MAA) tool and both organisations would cooperate in the field of harmonisation of accreditation by ILAC full members and peer assessments organised by the document Guide for the application of ISO/IEC Guide 65 to legal metrology was to be revised to bring it into line with other ISO standards, notably ISO 17021 and ISO 9001. A new MoU was signed on 28 October 2010 during the ILAC/IAF Joint General Assembly in Shanghai. On 16 October 2014 at the IAF ILAC Joint General Assembly, held in Vancouver, Canada, a renewed MoU was signed by Mr. Peter Unger (ILAC Chair), Mr. Randy Dougherty (IAF Chair) and Mr. Peter Mason (CIML President). Lastly, on 10 October 2018 at the 53rd CIML Meeting, held in Hamburg, Germany, a renewed MoU was signed by Ms. Merih Malmqvist Nilsson (ILAC Chair), Mr. Xiao Jianhua (IAF Chair) and Dr. Roman Schwartz (CIML President). The updates in the 2018 renewed MoU are mainly editorial in nature, most notably to address the OIML Certification System (OIML CS) and to consolidate some parts of the existing text.