Atomic Clocks
>Get the EXACT time - US Naval "Atomic" Master Clock
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Imagine a clock so smart it sets itself automatically and even corrects itself for daylight-saving time. The radio-controlled clock will do all this for you. Self setting clocks are not only the ultimate in convenience, they're also the ultimate for accuracy- you will always have the exact time! They say even a clock that doesn't work is right twice a day, but radio-controlled "atomic clocks" are ALWAYS right!
Atomic clocks receive a radio signal from the cesium atomic clock, the most accurate clock in the world, transmitted from the National Institute of Standards in Fort Collins, CO. The radio signal covers the entire United States and will keep your clock accurate to within one second over one million years. You'll never have to reset the clock, even for daylight-saving time!
The US Naval Observatory which operated 70 "atomic clocks" provided the following background information about these clocks: 'A cesium beam atomic clock uses the exact frequency emitted by atoms of the metallic element cesium. Today, cesium clocks measure frequency with an accuracy of one second in 1,400,000 years! It is the most accurate realization of a unit that man has yet achieved. A cesium clock operates by exposing cesium atoms to microwaves until they vibrate and counting the corresponding cycles as a measure of time.
Cesium clocks come in two types: a "laboratory (or primary) standard" about as large as a railroad flatcar and a "commercial (or secondary) standard" about as large as a suitcase. Only a few laboratory standards exist; they are used at research labs for frequency measurements of the highest accuracy. An example is the NIST-7 standard at the National Institute of Standards and Technology in Boulder, CO. Commercial standards, being industrially produced, are cheaper, but still provide state-of-the-art precise measurement of time.
The U.S. Naval Observatory operates about 70 cesium clocks, in 18 temperature and humidity controlled vaults. Time-interval counters compare each clock's time against that of one "Master Clock," whose frequency is steered to match its time to the average of the other clocks. This time is the Observatory's measure of the atomic time called Coordinated Universal Time (UTC). Sometimes cesium clocks are transported to remote locations to synchronize other clocks.
Get the EXACT time - US Naval "Atomic" Master Clock Shop For Atomic Clocks
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