In accordance with the Units and Time Act (EinheitZeitG), the PTB is responsible for ensuring the uniformity of measurement. This includes, in particular, the propagation of the units of measure within the meaning of measurement technology traceability. For the propagation of the units, the PTB primarily operates accredited laboratories. To promote uniformity in metrology, and with the aim of an extended professional support, on the 3rd May, 2011, a committee was established with the PTB for the development of measurement technology bases for calibration, in which the PTB and accredited calibration laboratories cooperate closely. This body has the title “Deutscher Kalibrierdienst (DKD)” - German Calibration Service - and is under the direction of the PTB.