La Crosse Technology WS-9020U Weather Radio User Manual


 
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a random security code is assigned by the sensor at start-up, and this
code must be received and stored by the intelligent weather station in
the first few minutes of power being supplied to it.
BATTERY CHANGE:
It is recommended to replace the batteries in all units on an annual
basis to ensure optimum accuracy of these units.
Please participate in the preservation of the environment.
Return used batteries to an authorized facility.
ABOUT 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 and date 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 intelligent
weather station. However, due to the nature of the Earth’s Ionosphere,
reception is very limited during daylight hours. The intelligent weather
station will search for a signal every night when reception is best. The
WWVB radio station derives its signal 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 information on the atomic clock and WWVB
please see the NIST website at
http://www.boulder.nist.gov/timefreq/stations/wwvb.htm
.