Logo of the Physikalisch-Technische Bundesanstalt
Panoramic view of the clock hall at PTB with the four caesium clocks CS1, CS2, CSF1 and CSF2.

Unit of Time

Working Group 4.41

The atomic fountain clock CSF1 of PTB

The caesium fountain clock CSF1 was built up during 1996 - 1999. A second fountain clock, CSF2, with improved accuracy was put into operation in 2008.