Atomic clocks used today are based on physics technology that involves
cold atoms and atomic fountains. A real atomic clock contains an
atomic oscillator and uses its frequency to measure the passage of
time. Some so-called atomic clocks are actually radio controlled
clocks that contain miniature radio receivers and use a quartz crystal
to keep time. These clocks rely on an atomic clock located elsewhere
to maintain their timekeeping precision.
Early atomic clocks were actually masers with equipment attached.
The first accurate atomic clock was built in London in 1955, by a man
named Louis Essen. Following the building of this clock, it was
internationally agreed that the definition of the second was based on
atomic time.
So, how exactly does an atomic clock work? The atomic clock's core
is comprised of a microwave cavity. Inside this cavity is ionized
gas, a radio oscillator, and a feedback loop. The feedback loop is
used to adjust the oscillator. The oscillator must be adjusted to
the frequency of the absorption characteristic defined by the individual
atoms' behavior.
The National Institute of Standards and Technology, based in Boulder,
Colorado, operates an atomic clock and broadcasts the standard time
on radio station WWVB, at a frequency of 60 kHz. Radio controlled
clocks periodically receive this 60 kHz radio signal to synchronize
their time with the NIST atomic clock.
If you wish to access the atomic clock on your personal computer, via the
Internet, Atom Time
is a desktop Windows application that connects to the Atomic Clock
time server computer and fetches the current time value. It compares
your PC time to this value and displays the difference.
Whether you wish to purchase a radio controlled, atomic clock or are
simply looking for more information on atomic clocks, the resources
on AtomicClocks.us will have the answers you are looking for. Take
some time to peruse the suppliers and information sources listed below.