caesium standard
primary frequency standard in which the photon absorption by transitions between the two hyperfine ground states of caesium-133 atoms is used to control the output frequency
en-US/ˈsiziəm ˈstændɚd/
en-GB/siːzjəm ˈstændəd/
primary frequency standard in which the photon absorption by transitions between the two hyperfine ground states of caesium-133 atoms is used to control the output frequency