Welcome to the 2021 World Metrology Day Resource website. The theme for World Metrology Day 2021 is Measurement for Health. This theme was chosen to create awareness of the important role measurement plays in health, and thus in the wellbeing of every one of us. Indeed more widely metrology, the science of measurement, plays a central role in scientific discovery and innovation, industrial manufacturing and international trade, in improving the quality of life and in protecting the global environment. World Metrology Day is an annual celebration of the signature of the Metre Convention on 20 May 1875 by representatives of seventeen nations. 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. The World Metrology Day project is realized jointly by the BIPM and the OIML. We hope that you enjoy this site and that your Country or Metrology Organization will join us and participate in this year's event.