World Metrology Day for 2015 has adopted the theme “Measurements and Light”. World Metrology Day is held on the 20th May each year and marks the signature of the Metre Convention by 17 nations in Paris in 1875. The Metre Convention now has 56 Member States and 41 Associate States, all of which use World Metrology Day as a focus for promoting the importance of measurement.

The theme for World Metrology Day 2015 is ‘Measurements and Light’. The topic was chosen to align with the UNESCO International Year of Light and Light-based technologies 2015 (IYL 2015), a global initiative designed to highlight the key role light and optical technologies play in our daily lives and their importance for our future and for the sustainable development of the society we live in.

Metrology plays a central role in enabling the application of light-based technologies, and in turn, light is at the heart of many of the most important new elements of leading-edge measurement technologies.

World Metrology Day is an annual celebration of the signature by representatives of seventeen nations of the Metre Convention on 20 May 1875. The Convention set the framework for global collaboration in the science of measurement and in its industrial, commercial and societal applications. The original aim of the Metre Convention - the world-wide uniformity of measurement - remains as important today as it was in 1875