Since 1999, PTB utilizes synchrotron radiation at the storage ring BESSY II in Berlin-Adlershof, continuing the work which started already at the former BESSY I storage ring which has been closed at the end of 1999. The PTB laboratory developed into an European center for radiometry, used by collaboration partners worldwide.
The PTB departments 7.1 and 7.2 operate a laboratory at BESSY II with currently nine experimental stations. Synchrotron radiation is calculable, so that BESSY II can be utilized as a primary source standard. Furthermore, with a cryogenic electrical substitution radiometer (ESR), the laboratory is equipped with a primary detector standard. Reflectometers are used for the characterization of optical components. At its beamlines, PTB offers a broad spectrum of services and calibrations with radiation from the UV to the X-ray range, reaching from routine measurements to powerful metrological system designs in cooperation with partners from industry and research.
The measurement capabilities are significantly extended by the Metrology Light Source, the new PTB-storage ring dedicated to metrology with synchrotron radiation.

| no. | beamline | photon energy |
| 1 | plane grating monochromator | 30 eV to 1800 eV |
| 2a | four crystal monochromator | 1.75 keV to 10 keV |
| 2b | fixed energy monochromator | 2.5 keV |
| 3a | undispersed bending magnet radiation | |
| 3b | normal incidence monochromator radiation for source calibration | 3 eV to 35 eV |
| 3c | deflected bending magnet radiation (UV and EUV spectral range) | |
| 4a | undispersed undulator radiation | |
| 4b | plane grating monochromator at undulator | 78 eV to 1860 eV |
| 4c | deflected undispersed undulator radiation |
Outside of PTB laboratory at the BAMline:
| no. | beamline | photon energy |
| 5a | multilayer crystal monochromator | 8 keV to 60 keV |
| 5b | undispersed wavelength shifter radiation |