Davis Instruments Vantage Pro2 manual Appendix a Weather Data

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Appendix A

Weather Data

Refer to this appendix to learn more about the weather variables that are measured, displayed, and logged by your Vantage Pro2 Station. Some weather variables require optional sensors. See “Optional Sensors” starting on page 2.

Wind

The anemometer measures wind speed and direction, and is part of the Integrated Sensor Suite (ISS). The console calculates a 10-minute average wind speed and 10-minute dominant wind direction. The 10-minute aver- age wind speed is displayed in the console ticker whenever wind has been selected on the console. The last six 10-minute dominant wind directions are included in the compass rose wind display.

Temperature

The ISS houses the outside temperature sensor in a vented and shielded enclosure that minimizes the solar radiation induced temperature error. The console houses the inside temperature sensor. Additional temperature sensors are available for wireless stations and can be used to measure up to eight locations.

Apparent Temperatures

Vantage Pro2 calculates three apparent temperature readings: Wind Chill, Heat Index, and the Temperature/Humidity/Sun/Wind (THSW) Index. Apparent temperatures use additional weather data to calculate what a human body perceives the temperature to be in those conditions.

Wind chill

Wind chill takes into account how the speed of the wind affects our per- ception of the air temperature. Our bodies warm the surrounding air mole- cules by transferring heat from the skin. If there’s no air movement, this insulating layer of warm air molecules stays next to the body and offers some protection from cooler air molecules. However, wind sweeps that comfy warm air surrounding the body away. The faster the wind blows, the faster heat is carried away and the colder you feel.

Heat Index

The Heat Index uses temperature and the relative humidity to determine how hot the air actually “feels.” When humidity is low, the apparent tem- perature will be lower than the air temperature, since perspiration evapo- rates rapidly to cool the body. However, when humidity is high (i.e., the air is more saturated with water vapor) the apparent temperature “feels” higher than the actual air temperature, because perspiration evaporates more slowly.

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Contents Vantage Pro2 Console Manual Vantage Pro2 Console Display Features Vantage Pro 2 Console ManualTable of Contents Keyboard & Display Console FeaturesChapter Welcome to Vantage Pro2 Printed on that keyOptional Sensors Vantage Pro OptionsConsole Modes Optional WeatherLink SoftwareOptional Accessories Installing the AC Power Adapter Chapter Installing the ConsolePowering the Console Ies provide backup power for up to four to six weeksInstalling Batteries Connecting Cabled StationsTested and established Installation ManualConsole Location Cabled consoleTable & Shelf Placement Wall Mounting Setup Mode Chapter Using Your Weather StationSetup Mode Commands Screen 1 Active Transmitters Screen 1 Active TransmittersScreen 3 Retransmit Wireless Only Screen 2 Configuring Transmitter IDs Wireless OnlyScreen Screen 4 Time & Date Screen 5 Latitude Screen 6 Longitude Screen 7 Time ZoneScreen 8 Daylight Savings Settings Screen 9 Daylight Savings Status Screen 10 ElevationScreen 11 Wind Cup Size Screen 12 Rain Collector Screen 13 Rain Season Data logger installed on the consolePress and release 2ND and press Units once Screen 14 Serial Baud RateCurrent Weather Mode Clear All CommandSelecting Units of Measure Selecting Weather VariablesSelected variable’s units will change. Repeat Press Wind to select wind speedPress 2ND then press Chill to select Wind Chill Wind Chill is displayed in either Fahrenheit ºF or CenPress 2ND then press Heat to display the Heat Index Night. Any rain accumulated in the last 24 hours displays Press Rainday to display the rain accumulated since 12 midTicker at the bottom of the screen Press 2ND then press Lamps to turn on the backlight for Screen display. Press 2ND then Lamps again to turn the backDisplaying the Forecast Calibrating, Setting, and Clearing VariablesCalibrating Temperature And Humidity Displaying Time & Date or Sunrise & SunsetCalibrate Wind Direction Reading After a moment, the variable you’ve selected beginsReading Calibrating Barometric Pressure Setting Weather VariablesClearing Weather Variables Highs and Lows Mode Viewing Highs and Lows Alarm Mode Four Special AlarmsSetting the Time Alarm Setting AlarmsClearing Alarm Settings Silencing Alarms Graph ModePress Done to silence an alarm when it sounds Viewing Graphs Weather Variable Available Graphs Vantage Pro2 Troubleshooting Guide Chapter Troubleshooting and MaintenanceProblem Solution Rain Console Diagnostic Screens Accessible to a cabled weather stationNumber of packets containing errors that were received Number of missed data packetsReception Diagnostic Screen Console Maintenance One Year Limited WarrantyAppendix a Weather Data Tive humidity 30% even though water vapor content does not changeSor Ity has a large capacity to absorb extra water vaporBarometric Pressure MED for persons with very light skin Pro2 displays UV readings in two scales MEDs and UV IndexSkin Phototype Skin color Tanning & Sunburn history Skin Type Skin Color History of Tanning & Sunburning IIIIndex Values Exposure Category Wireless Communication Specifications Appendix B SpecificationsConsole Console Data Display Specifications Weather Data Specifications Variable Required SensorsThsw Vantage Pro2 Console Icons Forecast