Dimensions:
- Case: 1-11/16" x 1-9/16" x 1/2"
- LCD: 1/2" x 13/16"
- Time display:
3/16"
- Band Length:
6-1/4" x 13/16"
- Fits wrists up to 8-3/4" (222 mm)
- Removable links to adjust size down in 3/8" (10 mm)
increments (20 total links)
- Additional links to lengthen band available
Radio-controlled Time:
The NIST (National Institute of
Standards and Technology-Time and Frequency Divisions) maintains
a radio station, WWVB, in Ft. Collins, Colorado. 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.
WWVB (the station’s
identification just like any other radio station) continuously
broadcasts time and frequency signals at 60 kHz. The carrier
frequency provides a stable frequency reference traceable to the
national standard. There are no voice announcements on the
station, but a time code is synchronized with the 60 kHz carrier
and is broadcast continuously at a rate of 1 bit per second
using pulse width modulation. The time code contains the year,
day of year, hour, minute, second, and flags that indicate the
status of Daylight Saving Time, leap years, and leap seconds.
The LaCrosse Technology WT-961B
Atomic Watch:
Our La Crosse radio-controlled
atomic watch maintains its incredible accuracy by automatically
tuning into the WWVB radio signal.
The Atomic Watch contains a small
but highly powerful antenna, specifically tuned for optimal
reception of the 60 kHz time signal. The signal received on the
antenna is demodulated by a tiny onboard receiver, which sends
the information to the watch's ultra-low-power CMOS
microprocessor for decoding. Once your watch has automatically
set its time for the first time, it ensures continuing accuracy
by automatically tuning into the WWVB radio signal once per day
after midnight. As long as your wristwatch is kept within
transmitter range, your Atomic Watch will continue to display
the absolutely precise time, even performing automatically the
adjustment for summer time/winter time changeovers. Should you
move your watch out of transmitter range for an extended period
of time, your Atomic Watch will still continue to operate as a
highly accurate quartz controlled clock. Upon re-entering the
transmitter range, your watch will correct itself again to the
precise WWVB time signal.
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