Physikalisch-Technische Bundesanstalt (PTB)

Research Organizations

The Physikalisch-Technische Bundesanstalt (PTB) is Germany's national metrology institute and the highest authority on correct and reliable measurement in the country. Founded in 1887 and today a scientific and technical federal authority under the Federal Ministry for Economic Affairs and Energy, it works in Braunschweig and Berlin. Its Optics division maintains the national standards for photometry and radiometry, from the candela to spectral measurements, to which lighting manufacturers and test laboratories trace their light measurements.