Atomic clocks, such as those based on the cesium-133 or rubidium-87 isotopes, operate by measuring the vibrations or oscillations of atoms. The signal from an atomic clock is typically not sent out continuously but rather transmitted at regular intervals.
The most common type of atomic clock is the cesium atomic clock, which operates by measuring the hyperfine transition of cesium-133 atoms. These clocks usually send out a signal once per second. This signal serves as a reference for precise timekeeping and synchronization of various systems.
However, it's worth noting that atomic clock signals are primarily used for time dissemination and synchronization purposes rather than being broadcast continuously for public consumption. The signals are typically received by various institutions, laboratories, and organizations responsible for maintaining accurate time standards and distributing them to other devices and networks.