Automatically on time
The advantages of radio-controlled watches are obvious: Once they have been set to the relevant time zone, they always display the exact local time. All CASIO radio watches receive signals almost anywhere in Europe. Some models even receive signals in North America, parts of Canada and Mexico (the radio tower in Fort Collins sends signals for a radius of up to 3,200 km) and even in Japan or China.. In Europe, the change from summer to winter time is also completely automatic. Here you can learn about the technology that makes it possible, and about how your watch picks up the time.
Why have a radio-controlled watch?
Regular signal reception ensures that your watch always shows the correct time. The exact time is transmitted to the watch from atomic clocks - the most precise watches in the world. No setting, no resetting, always on time.
Where does the time come from?
Atomic clocks are the most accurate clocks in the world. In Germany, the official time is established in the Physkalisch-Technische Bundesanstalt in Braunschweig the national meteorology institute. In Great Britain, the National Physical Laboratory in Teddington near London is in charge of this task.In the USA, this job is carried out by the National Institute for Standards and Technology (NIST) in Fort Collins/Colorado. In Japan, the official time is determined by the Communications Research Laboratory (CRL) in Tokyo. In China, the time is sent by the National Time Service Center.
How accurate are atomic clocks?
Atomic clocks hardly deviate at all from ideal time. Over a period of one million years, they could "theoretically" fall approx. one second out of sync. To put this into perspective: a quartz wristwatch falls a few seconds out of sync each month. Mechanical wristwatches - no matter how sophisticated they are - lapse many more seconds behind.
How does the time reach the watch?
The time calculated by atomic clocks is sent to radio towers.In Germany, the tower is located in Mainflingen near Frankfurt. In Great Britain, the tower can be found in Anthorn. In the USA, the tower is located in Fort Collins. The tower in Japan can be found in Fukushima in the North East and Fukuoka in the South West. The tower for China is located in Shangqiu. The radio tower in Mainflingen reaches a watch with radio technology within a radius of up to 1,500 km depending on the model. A special feature of some CASIO radio watches is that they are equipped to receive signals from all six transmitters.
What kind of signal is transmitted?
In Germany, the time signal DCF77 is transmitted on the frequency 77.5 kHz. MSF is the signal from Great Britain and WWVB is the signal in the USA - both are transmitted with a frequency of 60 kHz. The two Japanese signals JJY are transmitted with a frequency of 40 kHz and 60 kHz. The Chinese signal BPC is sent on a frequency of 68 kHz. The radio-controlled watch decodes the relevant signal and displays the exact local time.
What happens when I travel?
All CASIO radio-controlled watches are easy to set to the relevant time zonesThe exact time guaranteed in Europe, North America and most of Canada and Mexico. Some models are even equipped with the new radio technology Multiband 6 and receive signals in Japan and most of China. Outside their reception range, CASIO radio watches continue to work as normal quartz watches.
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