Use a red marker or red paint and put a large X on one of the cups. Take your anemometer outside and measure the wind speed. To do so, count the number of times the cup with the red mark passes in front of you in 30 seconds. Multiply by two to get revolutions/rotations per minute (rpm).

Each cup is attached to the end of a horizontal arm, each of which is mounted on a central axis, like spokes on a wheel. When wind pushes into the cups, they rotate the axis. The faster the wind, the faster the cups spin the axis. How fast will your homemade anemometer whirl?

Place the anemometer out in the wind. The cups are already arranged to catch the breeze. Calculate the distance the reference cup will travel to revolve around the axis once by taking the length of its rod from the axis, doubling it and multiplying by the value of pi.

Make an anemometer.

1. Position the straws in the shape of a cross and tape the middle.
2. Then, push a straight pin through the center of the straws and into an eraser on the end of a pencil.
3. You should be able to blow on the cups so that they spin around in a circle.

Answer

• It is “used to measure” the speed of wind.
• It is “used to measure” the velocity of wind.
• It is “used to measure” pressure of wind.
• It is used to check the quality of the wind.
• It is used to check the direction of the wind.
• It is used to check the rate of flow of wind.
• It is used to read the pattern of weather.

The four most popular anemometer models are: Vane Anemometers, Thermal Anemometers, Thermal Anemometers with Velocity / Temperature Profiling and Cup Anemometers.

An anemometer is an instrument that measures wind speed. This type of anemometer has a spinning wheel. The stronger the wind blows, the faster the wheel rotates. The anemometer counts the number of rotations, which is used to calculate wind speed.

The anemometer working principle is, the air stream will cool a heated object because the cooling rate can be determined by the airflow speed. A fine wire that is electrically heated can be arranged within the airflow. Once the flow of air increases then the wire gets cool.

An anemometer measures wind speed. Indoors, an anemometer measures air speed, air velocity or air flow. The air flow rate in buildings is often measured in cubic feet per minute (CFM) using anemometers to assess the performance of heating, ventilation and air conditioning (HVAC) systems and equipment.

An anemometer is a device used for measuring wind speed, and is a common weather station instrument. The voltage will range from 0.4V (0 m/s wind) up to 2.0V (for 32.4m/s wind speed). That’s it! The sensor is rugged, and easy to mount.

In the tube anemometer the dynamic pressure is actually being measured, although the scale is usually graduated as a velocity scale.

The instruments used to measure wind are known as anemometers and can record wind speed, direction and the strength of gusts. The normal unit of wind speed is the knot (nautical mile per hour = 0.51 m sec-1 = 1.15 mph).

Anemometers measure wind speed and wind vanes measure wind direction. A typical wind vane has a pointer in front and fins in back. When the wind is blowing, the wind vane points into the wind. For example, in a north wind, the wind vane points northward.

Two ways we can measure the wind are speed, and direction: a windsock is a tool we can use to measure both. A windsock is a conical textile tube you may have seen at an airport or alongside a highway at a windy location. For example, a wind from the west will point a windsock to the east.

To determine wind direction, a wind vane spins and points in the direction from which the wind is coming and generally has two parts, or ends: one that is usually shaped like an arrow and turns into the wind and one end that is wider so that it catches the breeze.

The weather vane points toward the source of the wind because the balancing weight is at the point of the arrow. The surface area toward the back of the arrow is lighter, and therefore catches the breeze, and turns to distribute the air flow evenly on both sides of the arrow.

The disadvantage is wind vane is not accurate and unreliable at the time, does not show the speed of the wind, and depends on winds breezes and thus is unable to tell the high pressure and low pressure in the region.

Wind vane has a rotating ornament that points the direction at the top of the rod. It consists of a small globe at the top of the rod and a bigger one at the bottom of the rod. A direction pointer that indicates north, South, East, West is fixed to the rod between the two globes.

A wind vane (also known as a weathervane) is an instrument that tells you the wind direction. Specifically, a wind vane lets you know what direction the wind is coming from.