Physikalisch-Technische Bundesanstalt
The
Physikalisch-Technische Bundesanstalt (PTB) is based in
Braunschweig and
Berlin. It is the national institute of natural and engineering sciences and the highest technical authority for
metrology and physical safety engineering of the
Federal Republic of Germany
Part of its brief is the accurate measurement of time and it is responsible for the German atomic clock DCF77
External links