Message from the BIPM and BIML Directors
Martin Milton
Director of the BIPM
Anthony Donnellan
Director of the BIML
Measurements for all times, for all people
150 years of the Metre Convention
Each year World Metrology Day (20 May) offers us an opportunity to celebrate the international commitment to a harmonized global measurement system, based on what we now call the International System of Units (SI).
This year is particularly special because it also marks 150 years since the Metre Convention was signed and the Bureau International des Poids et Mesures (BIPM) was established.
To mark this auspicious occasion, in 2025 we are coming together as a global metrology community to celebrate what has been achieved over a century and a half, and to look forward to the opportunities and challenges that may lie ahead for the future of global measurement systems.
A Legacy of Evolution and Innovation
Measurement is fundamental to every aspect of our lives – from trading goods, to monitoring our health, and observing and understanding the world around us. The original signatories of the Metre Convention understood this and had a vision that was clear and ambitious: to unify and improve measurement systems worldwide, establishing a system that would serve “for all times, for all people.”
From its foundation in 1875, the BIPM has tackled significant technological challenges to produce stable and accurate standards for the metre and the kilogram that would be suitable for use around the world.
By the twentieth century, the technical task grew further to address the needs for standards for temperature, light and electricity.
At the dawn of the twenty-first century, a new opportunity emerged to realize the SI on the fundamental constants of nature, ushering measurement science into the quantum era.
As accurate standards became available for more and more different types of measurement, and as science and industry evolved, so too did the need for internationally agreed standards to support their use. In 1955, the Organisation Internationale de Métrologie Légale (OIML) was therefore established to facilitate the integration of measurement standards into national laws and regulatory frameworks, ensuring consistency in the use of measuring instruments worldwide.
Looking to the future
As the world around us evolves, so too must our measurement systems, ensuring they remain precise, universally accessible and capable of meeting the needs of future generations
The challenge before us is clear: to build a measurement framework that not only keeps pace with scientific discovery but also serves all nations, equitably and reliably. This is our shared responsibility and our collective opportunity.
We invite you to join us in celebrating this historic milestone not only to reflect on how far we have come, but also to commit to the exciting journey that lies ahead
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