La Crosse Technology WS-9626U-IT - Manuel (Page 22)

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ATOMIC AUTO-SET TIME FUNCTION - WWVB RADIO CONTROLLED TIME
The NIST (National Institute of Standards and Technology—Time and Frequency Division) WWVB
radio station is located in Ft. Collins, Colorado, and transmits the exact time signal continuously
throughout the United States at 60 kHz. The signal can be received up to 2,000 miles away through the
internal antenna in the weather projection station. However, due to the nature of the Earth’s
Ionosphere, reception is very limited during daylight hours. The wireless weather station will search for
a signal every night when reception is best.
The WWVB radio station receives the time data from the NIST Atomic clock in Boulder, Colorado. A
team of atomic physicists is continually measuring every second, of every day, to an accuracy of ten
billionths of a second per day. These physicists have created an international standard, measuring a
second as 9,192,631,770 vibrations of a Cesium-133 atom in a vacuum. For more detail, visit
http://www.boulder.nist.gov/timefreq.htm. To listen to the NIST time, call (303)499-7111. This number
will connect you to an automated time, announced at the top of the minute in “Coordinated Universal
Time”, which is also known as Greenwich Mean Time (GMT). This time does not follow Daylight Saving
Time changes. After the top of the minute, a tone will sound for every second. It is possible that your