Ever wondered exactly what a windsock does? The windsock, sometimes called a wind cone, is used to measure wind speed and direction. It has a history that goes back to early Rome, where it began its life as a military flag. Since then, it has been used in cultures around the world as a flag, standard or wind measurement instrument.
Measuring the direction of the wind
According to windsock specialists that provide windsocks direct online for aviation and industrial purposes, the wind blows into the larger end of the air hose causing the smaller end to point towards the direction to which the wind is flowing. Wind direction is given as a standard compass direction from where the wind originates. So, a windsock pointing to the west indicates a wind coming from the east – an east wind.
Wind speed measurement
A sleeve (air hose) is placed on a pole at a high point, so it can move freely in the wind, and be easily seen. Wind speed is indicated by the angle at which the sleeve hangs. The standard reference for wind speed (knots) is 15 – 17 mph for a fully inflated sleeve, and 3 knots as the minimum wind speed needed to move it from a vertically hanging position (zero wind).
Windsocks can be found at ports, airports and even on windy mountain roads. They provide a quick visual reference of wind conditions and can be critical for proper navigation. Sometimes they are also used at manufacturing plants, especially those manufacturing chemical products, as a measure to indicate potentially dangerous leaks/emissions.
Windsocks date back to around 100 AD. It is believed that the Romans first used conical banners to represent various military groups. The windsock of today has its origin in Japan and China where they were made of silk or even paper.
In Japan, koi-shaped wind sleeves, called koi noburi, are used to celebrate children’s day. A koi noburi is flown on a tall bamboo pole for the father of the house along with one for each of his children.
An essential element to avoid accidents associated with unexpected wind gusts
The windsock is a device that allows very precise information regarding the direction and force of the wind.
It is easy to measure the strength of the wind thanks to the different coloured parts of the sleeve.
Usually, a windsock comprises a tall pole, wind vane, and windsock.
The sock (air hose) is, typically, composed of five red and white stripes: three red bands and two white bands. The wind vane is used to show where the wind is going.
The pole, or mast, is normally equipped with a tilt axis (inclination of the top of the mast) that allows easy access to the sleeve to change it or simply to remove it when it is not useful.
Most chemical factories, exposed highways, aerodromes, etc. or wherever there is exposure to high wind benefit from being equipped with a windsock.
So, how is wind speed measured exactly?
Each ring of colour in the sock corresponds to a speed of approximately 3 knots or approximately 3.5 mph, so when all the bands are inflated, the wind speed is 5X3.5 or 17.5 knots. The wind speed is estimated from the angle of inclination of the sleeve with respect to the horizontal or to the pole, or mast.
Most windsock sleeves (air hoses) are made from polyester for durability. The mast, pole, or other mounting assembly is typically made of galvanized steel.
Windsocks can be used for a wide variety of applications and are available in a variety of sizes and configurations.