There are many times in industry when knowing how to measure wind direction is useful. It is a key element of safety in aviation, boating and winter sports, and must also be considered when designing structures, both permanent and temporary.
For example, in advertising, the wind load of a large unipole sign can be significant. Wind direction must also be considered in the event industry when setting up outdoor concert stages or large tents. Both types of structures are vulnerable to winds blowing from specific directions. For example, a unipole sign experiences a much higher load if the wind blows directly from the front. Wind direction is also a key variable used by meteorologists when forecasting the weather.
Knowing how to measure wind direction is also essential in the construction industry. It is especially important when dealing with high-rise buildings and tower cranes. Assuming wind speed is kept constant, the wind can become more or less dangerous depending on the direction from which it is blowing. Architectural design can also take advantage of local winds for passive ventilation, reducing dependence on mechanical ventilation and saving energy.
Measuring Wind Direction with a Weather Vane
Just like wind speed is measured by an anemometer, wind direction is measured by a weather vane or wind vane. It is possible to use multiple wind vanes spread across many locations to determine the broader wind profile of a geographic region, especially if they are installed along with anemometers.
The combination of an anemometer and a wind vane mounted together is often called an aerovane.
Once wind direction is measured, it can be reported in either cardinal directions or degrees:
- Cardinal Directions: It is important to note the direction from which the wind is blowing. For example, a westerly wind blows from west to east.
- Degrees: Alternatively, the wind can be reported in clockwise degrees counting from the north, which corresponds to 0°. Thus, 90° is equivalent to the east, 180° is equivalent to the south, and 270° is equivalent to the west.
The first wind vanes served mostly a decorative purpose rather than being a meteorological tool, and rooster-shaped wind vanes are common in European churches, given that the rooster is associated with Saint Peter. Wind direction measurement can also be used for recreational purposes: it is used in both golf and boating.
How to Measure Wind Direction with a Windsock
Another device that measures wind direction is the windsock, which uses a large cloth tube that extends depending on wind speed and direction. Windsocks are commonly used in airports and airfields. They can be spotted directly by pilots thanks to their large size and bright colours. Windsocks are also used in roads where the wind represents a risk, and are typically equipped with a floodlight to make them visible at night.
Windsocks are not intended for integration with electronic measurement systems. Their main purpose is to provide a visual indication of wind speed and direction. Keep in mind that each stripe in a windsock represents 3 knots. Since most windsocks are divided into 5 stripes, a fully extended one indicates a wind speed of at least 15 knots.
How WINDCRANE Measures Wind Direction
The WINDCRANE kit is compatible with a broad range of sensor inputs to measure wind direction, including proprietary and third-party wind vanes.
Data is stored in a cloud database at 10-minute intervals and can be viewed from a smartphone application through GSM. These features are very useful in the construction industry. Live snapshots of weather conditions across multiple sites allow project managers to schedule work more effectively without exposing personnel and equipment.