The International System of Units
May 20 is World Metrology Day, commemorating the anniversary of the signing of the Metre Convention in 1875. This treaty provides the basis for a coherent measurement system worldwide that underpins scientific discovery and innovation, industrial manufacturing and international trade, as well as the improvement of the quality of life and the protection of the global environment.
The theme for World Metrology Day 2019 is The International System of Units – Fundamentally better. This theme was chosen because on 16 November 2018, the General Conference on Weights and Measures agreed perhaps one of the most significant revisions to the International System of Units (the SI) since its inception. Research into new measurement methods, including those using quantum phenomena, underpin the change. The SI is now based on a set of definitions each linked to the laws of physics and have the advantage of being able to embrace further improvements in measurement science and technology to meet the needs of future users for many years to come.
Across the world, national metrology institutes continually advance measurement science by developing and validating new measurement techniques at whatever level of sophistication is needed. The national metrology institutes participate in comparisons coordinated by the Bureau International des Poids et Mesures (BIPM) to ensure the reliability of measurement results worldwide. The BIPM also provides a forum for its Member States to address new measurement challenges. The International Organization of Legal Metrology (OIML) develops International Recommendations, the aim of which is to align and harmonize requirements worldwide in many fields.
World Metrology Day recognizes and celebrates the contribution of all the people that work in intergovernmental and national organizations throughout the year on behalf of all.