The local UTC time scales are referred to by the
BIPM as UTC(k), where k is the acronym of the laboratory.
Woods, Update of the
BIPM comparison
BIPM.RI(II)-K1.F-18 of activity measurements of the radionuclide [sup.18]F to include the NPL.
Proper maintenance of the standards includes periodic recalibration at the
BIPM. There is no prescribed recalibration interval for the national standard K20, and during its more than 120 year existence, periods of several decades have elapsed between recalibrations.
It has been adopted by the Bureau International des Poids et Measures (
BIPM), the international body of Metrology in Paris that guides standardization in terms of SI units for all nations of the world.
Silvestri, Key comparison
BIPM.RI(I)-K2 of the air-kerma standards of the ENEA-INMRI, Italy and the
BIPM in low-energy x-rays, Metrologia 48 Tech.
International Atomic Time (TAI) and Coordinated Universal Time (UTC) are computed at the Bureau International des Poids et Mesures (
BIPM) in Sevres, France, from clock data that are contributed by timing laboratories from around the world.