(IMAGE) Physikalisch-Technische Bundesanstalt (PTB) Caption “Focus on Metrology” is the motto of the Helmholtz Prize. Credit (Photo: PTB) Usage Restrictions Credit must be given to the creator. License CC BY 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.