Unlike some small temperature stations, the WS-9013U simultaneously displays indoor and outdoor temperatures, so you don't have to actively select one or the other for viewing. If you're using more than one remote transmitter, you will have to select the desired channel for the outdoor temperature display. The station keeps a record of the minimum and maximum indoor and outdoor temperatures it has recorded (since the last memory reset) along with the times and dates of their occurrence. These are available at the push of a button and are displayed for 20 seconds, during which time the temperature flashes to let you know you have selected a record from memory. You can easily reset the temperature memory any time you want.

Not only will the station operate with up to three remote transmitters, three different transmitters are available. The TX6U (the one included with the station) reports outdoor temperature. The TX3UP senses temperature via a probe for use in pools, spas, soil, etc., and has an LCD display.

The station's clock calibrates itself to the world's most accurate clock every night by receiving WWVB radio transmissions. These transmissions contain time information from the U.S. atomic clock source, operated by the U.S. Commerce Department near Boulder, Colorado. The built-in antenna ensures reliable signal reception up to 2000 miles (3200km) from the WWVB transmitter.

The LCD panel on the WS-9013U can be set for any of 8 levels of contrast for optimum viewing. Please note that this station's LCD panel has no backlight, so it is not suitable for use in the dark.

The WS-9013U is cleanly and simply styled, with a two-tone case in semi-metallic colors that are not exactly shades of silver but not exactly shades of gold, either. We'd say they fall somewhere between the two, and they look great together. An integral folding stand allows the station to be used as a freestanding unit, or it can be mounted on a wall. With its small size (under 6 inches tall), handsome looks, and useful features, the WS-9013U is equally well suited to home and office environments where space is at a premium.

• Clock sets automatically to WWVB radio signal (manual setting is also possible).
• 12/24-hour time display (hour and minute, seconds indicated by flashing dot).
• 8 selectable time zones include GMT (0) plus 7 North American time zones: Atlantic (-4), Eastern (-5), Central (-6), Mountain (-7), Pacific (-8), Alaska (-9), and Hawaii (-10). Three-letter abbreviations are displayed for EST, CST, MST, PST, ALA, and HAW.
• Clock automatically adjusts for daylight saving time and displays DST when daylight saving time is in effect.
• DST time changes can be disabled if you live in an area (Indiana or Arizona) that does not observe DST.
• Calendar display (month, day).
• Station displays indoor and outdoor temperatures simultaneously.
• Integral temperature memory records minimum and maximum indoor and outdoor temperatures for display at any time.
• All minimum and maximum temperature recordings show date and time received, and the memory is resettable whenever desired.
• Temperature indication selectable for either °F or °C.
• One remote temperature transmitter included; additional transmitters are optional and sold separately.
• Main unit can receive and display information from up to three outdoor transmitters.
• LCD panel has 8 selectable contrast levels.
• Low-battery indication is provided.
• Station is powered by two AA (1.5V) alkaline batteries (not included), with average life of about 1 year.
• Remote transmitter powered by two AA (1.5V) alkaline batteries (not included), with average life of about 1 year. For use in sub-freezing conditions, lithium AA batteries are recommended instead of alkaline.
• Remote transmitter is wall-mount only.
• Table stand of main unit is removable for wall mounting.

• Radio-controlled time signal: WWVB, 60 kHz
• Indoor temperature measuring range:
  32° to 139.8°F with 0.2°F resolution
  (0° to 59.9°C with 0.1°C resolution)
  ("OFL" is displayed if outside this range)
• Outdoor temperature measuring range:
  -21.8° to 157.2°F with 0.2°F resolution
  (-29.9° to 69.9°C with 0.1°C resolution)
  ("OFL" is displayed if outside this range)
• Indoor temperature checking interval:
  every 10 seconds
• Outdoor temperature checking interval:
  every 1 minute by remote, with outdoor temperature reception by station every 5 minutes
• Station dimensions (with folding stand not extended):
  3.18 inches (81 mm) wide
  5.62 inches (143 mm) high
  1.25 inches (32 mm) deep

• Remote transmission of outdoor temperature to station via 433.92 MHz signals
• Transmission range: 82 feet (25m) in open space with no interference
• Temperature checking interval: every 1 minute, with reception by station every 5 minutes
• Rainproof case
• Wall mounting
• Remote transmitter dimensions:
  1.57 inches (40 mm) wide
  5.04 inches (128 mm) high
  0.9 inch (23 mm) deep

The atomic clock integral to the WS9013U maintains its incredible accuracy by automatically tuning into the WWVB radio signal. The built-in antenna ensures reliable signal reception up to 2000 miles (3200 km) from the WWVB transmitter. As a result, the clock will calibrate to the atomic clock not only throughout the mainland U.S. but also in much of Canada. You need only insert the batteries, wait until the signal is received, and program the desired additional settings. In locations outside of WWVB range, the clock can be manually set and will provide the high degree of accuracy of any quality quartz clock.

In a nutshell, here's how the the atomic clock works: The clock's antenna is specifically tuned for optimal reception of the 60 kHz time signal. The time signal received on the antenna is demodulated by an onboard receiver, which sends the information to the clock's CMOS microprocessor for decoding. Once your clock has automatically set its time for the first time, it ensures continuing accuracy by automatically tuning into the WWVB radio signal between midnight and 6:00 a.m. As long as your clock is kept within transmitter range, it will continue to display the absolutely precise time, automatically adjusting for summer time/winter time changeovers if the daylight saving time option is ON. Should you move your clock out of transmitter range for an extended period of time, the clock will continue to operate as a highly accurate quartz-controlled clock. Upon re-entering the transmitter range, your clock will correct itself again to the precise WWVB time signal.