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 longwave 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, Colorado 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 savings time, and vice versa, takes place automatically with the same precision.

For more information on the NIST and radio controlled time, see http://www.boulder.nist.gov/timefreq/stations/wwvb.htm

Air Pressure Tendency Arrow
Forecast Icon Based on Changing Air Pressure
Indoor humidity (%RH)
Records MIN & MAX (indoor) Humidity w/ Time & Date Stamp
Barometric Pressure Display & Histogram for the Last 12 Hrs
Monitors Indoor & Outdoor Temperature (F or C)
Records MIN & MAX Temperature w/ Time & Date Stamp
Radio Controlled Time & Date
Calendar
Time Zone Map
Wall Hanging or Free Standing
Detachable Stand Included
Specifications:
Indoor temperature range: 32F to 140F
Remote temperature range: -21.8F to 156.2F
Temperature accuracy: +/- 1.5F
Humidity range: 20% to 95%
Transmission frequency: 433.92 MHz
Transmission range: Up to 80 feet open
Dimensions: 9.13" x 3.75" x 2.75"

Radio controlled time and date
Current moon phase
Indoor temperature and humidity
Outdoor temperature and humidity
Forecast icon
Weather tendency indicator
Min/max temperature records
LED Backlight
Can receive up to 3 transmitters
Indoor temperature range: 32°F to 140°F
Remote temperature range: -21.8°F to +156.2°F
Temperature Accuracy: +/- 1.5°F
Power requirements (receiver): 2 AA Batteries
Humidity range: 20% to 95%
Humidity accuracy: +/- 3%
Power requirements (remote):
2 “AA” Alkaline batteries
Transmission Frequency: 433.92 MHz
Transmission Range: Up to 80 feet open air

item # WS 9025