The Atomic Clock
To define the time as accurately as possible, the Cesium atoms are measured in different energetic conditions:
The Cs-atoms evaporate in an oven and get magnetically sorted, whereby only atoms of a low energetic condition get into the cavity. There, the atoms are animated to change their condition through radiotherapy with a microwave field. The atoms that changed their condition are collected in a special chamber. At a certain frequency, the amount of collected atoms is on its climax. This frequency is hold an counted.
One second is exactly after 9,192,631,770 period durations over.
The difference of the atomic clock while one year is maximal 25-12 billionths seconds in relation to an ideal clock. A quartz watch has deviation of a few seconds per month, mechanical watches have significantly larger deviations.
Important international time signal transmitter
To transfer the exact time of an atomic clock, for instance onto radio controlled watches, there are worldwide different time signal transmitter.
The most important ones that offer this service public are:
- DCF77 (Germany) in Mainflingen in Hessen
- MSF (Great Britain) in Anthorn
- JJY (Japan)
- WWV (USA) in Fort Collins
- WWVH (USA) on Hawaii
- BPC (China) in Shangqiu
So called multifrequent radio controlled watches
can receive the signal of a few time signal transmitters (mostly DCF, MSF, JJY and WWV). With these watches one can synch the time in most parts of the world.
An absolutely world first are the Astron GPS solar watches. With an GPS-receiver in the watch, which immediately synchs the position with the stored timezone, the Seiko Astron watches
set the time nearest second, no matter where you are. It is a technical sensation and therefore the ultimate worldtime watch, that works everywhere without time signal transmitters.
Meanwhile, there are more GPS world time watches
of different watch brands built on similar technology, so that we have created a special watches category for this purpose.