Weather Data Measured & Calculated

on our perception of the temperature.The THSW Index requires a solar radia- tion sensor.

Humidity

Humidity itself simply refers to the amount of water vapor in the air. However, the amount of water vapor that the air can contain varies with air temperature and pressure. Relative humidity takes into account these factors and offers a humidity reading which reflects the amount of water vapor in the air as a per- centage of the amount the air is capable of holding. Relative humidity, there- fore, is not actually a measure of the amount of water vapor in the air, but a ratio of the air’s water vapor content to its capacity. When we use the term humidity in the manual and on the screen, we mean relative humidity.

It is important to realize that relative humidity changes with temperature, pres- sure, and water vapor content. A parcel of air with a capacity for 10 g of water vapor which contains 4 g of water vapor, the relative humidity would be 40%. Adding 2 g more water vapor (for a total of 6 g) would change the humidity to 60%. If that same parcel of air is then warmed so that it has a capacity for 20 g of water vapor, the relative humidity drops to 30% even though water vapor content does not change.

Relative humidity is an important factor in determining the amount of evapo- ration from plants and wet surfaces since warm air with low humidity has a large capacity for extra water vapor.

Dew-Point

Dew-point is the temperature to which air must be cooled for saturation 100% relative humidity) to occur, providing there is no change in water content. The dew-point is an important measurement used to predict the formation of dew, frost, and fog. If dew-point and temperature are close together in the late after- noon when the air begins to turn colder, fog is likely during the night. Dew- point is also a good indicator of the air’s actual water vapor content, unlike rel- ative humidity, which takes the air’s temperature into account. High dew-point indicates high vapor content; low dew-point indicates low vapor content. In addition a high dew-point indicates a better chance of rain and severe thunder- storms. You can even use dew-point to predict the minimum overnight temper- ature. Provided no new fronts are expected overnight and the afternoon Relative Humidity ≥ 50%, the afternoon’s dew-point gives you an idea of what minimum temperature to expect overnight, since the air is not likely to get colder than the dew-point anytime during the night.

Rain

Vantage Pro2 incorporates a tipping-bucket rain collector in the ISS that mea- sures 0.01'' for each tip of the bucket. A metric adapter can be installed to mea- sure 0.2 mm for each tip of the bucket.Your station logs rain data in the same units it is measured in and converts the logged totals into the selected display

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DAVIS Vantage Pro2 manual Humidity, Dew-Point, Rain
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Vantage Pro2 specifications

The DAVIS Vantage Pro2 is an advanced weather station designed for both amateur enthusiasts and professional meteorologists. This comprehensive weather monitoring solution offers a plethora of features that provide real-time data for a variety of atmospheric conditions. The Vantage Pro2 is equipped with a suite of sensors that measure temperature, humidity, barometric pressure, rainfall, wind speed, and wind direction.

One of the standout characteristics of the Vantage Pro2 is its ability to offer accurate readings over a wide range of environmental conditions. The integrated radiometer ensures precise solar radiation and UV readings, making it an excellent tool for agricultural professionals and outdoor event planners. The station’s robust design includes an outdoor sensor suite that is both waterproof and built to withstand harsh weather, making it suitable for use in diverse climates.

Key technologies incorporated into the Vantage Pro2 include wireless transmission capabilities, allowing data to be sent to a console or computer without the need for cumbersome cables. The transmission distance can extend up to 1,000 feet (300 meters) under optimal conditions, ensuring flexibility in sensor placement. The console features user-friendly software that enables real-time graphing as well as historical data tracking, making it easy for users to analyze trends over time.

The Vantage Pro2 also supports optional features like the WeatherLink data logger, which provides additional storage and the ability to share data online or directly to mobile devices. This connectivity allows users to monitor weather patterns from anywhere, making it an invaluable tool for those who rely on up-to-date weather information for decision-making.

Ease of installation is another advantage of the Vantage Pro2. The setup process is straightforward, enabling users to begin monitoring their weather conditions quickly. The sensors are designed to be low maintenance, with battery-powered options lasting up to two years, reducing the hassle of frequent replacements.

In summary, the DAVIS Vantage Pro2 is a comprehensive weather station that leverages advanced technology to provide accurate, real-time data. Its robust features, wireless capabilities, and user-friendly interface make it an indispensable tool for anyone who needs reliable weather monitoring, from hobbyists to professionals in various fields. With its durability and versatility, the Vantage Pro2 stands out as a leader in personal weather stations.
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