Poster for World Metrology Day 2019 (IMAGE) Physikalisch-Technische Bundesanstalt (PTB) Caption The official poster for World Metrology Day 2019. Credit Ì Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.