In case the atomic clock is not able to detect the WWVB-signal (disturbances, transmitting distance,
etc.), the time can be manually set (please refer to notes on
Manual time setting
)
.
1.
Press the + key. The display should now show the
month&date/weekday/seconds/outdoor
temperature.
2.
Press the + key a second time and the display will now show the
month&date/weekday/indoor
temperature/seconds.
3.
Press the + key third time and the display will now show the
month&date/seconds/indoor
temperature/outdoor temperature
POSITIONING
Before permanently mounting ensure that the atomic clock is able to receive WWVB signals from the
desired location. Also, extreme and sudden changes in temperature will decrease the accuracy of the
atomic clock, and changes in elevation will result with inaccurate temperatures readings for the next
12 to 24 hours. These changes will require a 12 to 24 hour wait before obtaining reliable data.
4.
Press the + key a fourth time and the display will return to the normal display.
WWVB RADIO CONTROLLED TIME
The NIST radio station, WWVB, 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 atomic clock. However, due to the nature of the Earth’s
Ionosphere, reception is very limited during daylight hours. The atomic clock 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 continually measures every second of every
day to an accuracy of ten billionths of a second a 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. This
atomic clock regulates the WWVB transmitter.
To achieve a true temperature reading, avoid mounting where direct sunlight can reach the outdoor
temperature transmitter. It is recommended to mount the outdoor temperature transmitter on a North-
facing wall or in any well shaded area. The maximum transmitting range is 82 feet (25 meters)
obstacles such as walls, concrete, and large metal objects can reduce the range.
Place both units in their desired location, and wait approximately 10 minutes before permanently
mounting to ensure that there is proper reception. The outdoor temperature transmitter is not
waterproof and should not be placed anywhere it will become submerged in water or be directly in the
rain.
Once the outdoor temperature is displayed on the atomic clock, the WWVB tower icon in the clock
display will start flashing in the top center of the LCD. This indicates that the clock has detected a
radio signal and is trying to receive it. When the time code is received, the WWVB tower becomes
permanently lit and the time will be displayed.
POSITIONING THE ATOMIC CLOCK:
There are two possible ways to mount the atomic clock:
•
use of the foldout table stand, or
If the tower icon flashes, but does not set the time or the WWVB tower does not appear at all, then
please take note of the following:
•
wall mounting
FOLDOUT TABLE STAND
The foldout table stand leg is located on the backside. Pull the stand out from the
bottom center edge of the atomic clock, below the battery compartment. Once the
foldout table stand is extended, place the atomic clock in an appropriate location.
•
Recommended distance to any interfering sources like computer monitors or TV sets is a
minimum of 6 feet (2 meters).
•
Within ferro-concrete rooms (basements, superstructures), the received signal is naturally
weakened. In extreme cases, please place the unit close to a window and/ or point its front or
back towards the Fort Collins, Colorado, transmitter.
•
During nighttime, the atmospheric disturbances are usually less severe and reception is
possible in most cases. A single daily reception is adequate to keep the accuracy deviation
below 1 second.
Note:
