Frequency normal
A frequency standard is a frequency-stable oscillator . Today an atomic clock is mostly used as the frequency standard.
The derived frequency standards highly accurate frequencies are used as standard frequencies referred to, and are often with the carrier wave from time signal transmitters or radio stations in the long or medium waveband identical.
The realization of the second is based on an atomic transition in the cesium atom, the frequency of which is transferred in a frequency standard to the frequency of an external oscillator. The thermal motion of the atoms limits the accuracy of conventional cesium standards. Since the development of laser cooling technology , it has become possible to capture thermal atoms and cool them down to almost absolute zero . Since cold and therefore slow atoms can be observed for much longer, the accuracy of frequency standards has been greatly improved with this technology.
literature
- Wolfgang Bauer, Hans Herbert Wagener: Components and Basic Circuits of Electronics Volume 2 Basic Circuits. 1st edition, Carl Hanser Verlag, Munich Vienna, 1981, ISBN 3-446-12319-9