NOTHING IS MORE PRECISELY MEASURED THAN TIME!

And nothing keeps track of time more precisely and trouble free than La Crosse Technology radio controlled clocks.

Since the beginning of time, man has been fascinated with the measurement of time and has devised more accurate machines to trap and measure time. Today, time is precisely measured in the United States by the most accurate clock in North America, the Atomic Clock of the US National Institute of Standards and Technology, Time and Frequency Division in Boulder, Colorado. A team of atomic physicists continually measures 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. This atomic clock regulates the WWVB radio transmitter located in Fort Collins, Colorado, where the exact time signal is continuously broadcast throughout the United States at 60 kHz to take advantage of stable long wave radio paths found in that frequency range. Radio waves at these low frequencies use the earth and the ionosphere as a wave-guide and follow the curvature of the earth for long distances.

The built in antenna system will receive the WWVB signal anywhere in North America within 2000 miles of Fort Collins where long-wave radio reception is undisturbed. A microprocessor activates the receiver and processes the time signal from Fort Collins overnight.

Through the radio signals, La Crosse Technology radio controlled clocks always keep precise time. The changeover from standard time to daylight saving time, and vice versa, takes place automatically with the same precision.

ADDITIONAL DETAILS

To set up your clock simply install one fresh AA, LR6 ALKALINE battery. Due to the nature of long wave radio signals it is normally not possible to receive a signal during the day so it is best to install the battery late in the evening. Select your time zone by pressing one of the four time zone buttons PT-Pacific Time, MT-Mountain Time, CT-Central Time, ET-Eastern Time. The time zone buttons may be pressed any time after installing the batteries. If multiple buttons are pressed the clock will set to the time zone selected last. If no time zone is selected the clock will default to Pacific Time. Another time zone can be selected during or after the clock has set itself. Your clock can only set itself to one of the four time zones stated above. For time zones outside of PT, MT, CT or ET you must manually set the time using the Manual Time set button on the back of the movement.

Once the battery is installed the clock will begin searching for a signal. For the initial setting it is recommended to stand the clock in an upright position near a window. Within five minutes the clock will either receive the WWVB signal and set itself to the exact time, or it will determine that the signal is not receivable at its current location and time of day. If a signal is not receivable it will fast-forward the hands to the 4, 8, or 12 o’clock position and search for WWVB each hour until a signal is received. If the time is manually set the clock will continue to periodically search for a signal and automatically reset the hands when the signal is received.

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La Crosse Technology WT-3181 instruction manual Nothing is More Precisely Measured than Time, Additional Details