AnemometerBy Hammad HassanZeeshan Nayyar

What is Anemometer?• It is a measuring device used for measuring

Wind speed or Wind Pressure.

• It is a common weather station instrument.

• There is a close connection between the pressure and the speed, an anemometer designed for

one will give information about both.

Anemometer• Anemometer are of many kinds but we will tell

the working of that type which we are going to make.

Cup Anemometer

• A cup anemometer could have 3 or 4 cups.• The air flow past the cups in any horizontal

direction and turn the shaft in a manner that is proportional to the wind speed.

• Count the turns of the shaft over a set time period.

• This gives Average speed of wind.

Cup Anemometer

Comparison of 3 and 4 Cup Anemometer3 Cup Anemometer 4 Cup Anemometer• It had an error of less than

3% up to 60 mph (97 km/h). 

• In it each cup produces maximum torque when it was at 45 degrees to the wind flow. The three cup anemometer also had a more constant torque and responded more quickly to gusts than the four cup anemometer.

• With four cups it is easy to see that since the cups are arranged symmetrically on the end of the arms, the wind always has the hollow of one cup presented to it and is blowing on the back of the cup on the opposite end of the cross.

• It gives 33.3% of error when speed of wind is more than 60 mph.

Construction• It could be made by household things.

• And also by any special arrangements.

• To make an anemometer we need three cups with rods; connected to each other by a single vertical shaft or some block connected to shaft that could rotate. The joints could be welds or some other type.

Construction

• Now we need to construct a mounting block which will hold the vertical shaft to which wind cups will be attached and allow the wind cups to rotate freely. This holding and rotating is possible by bearing collar assembly.

Construction

• Attach the cups to vertical shaft and its holding assembly. Mark one of the cup (X).

• The Anemometer is ready to measure the wind speed. We will be needing a stopwatch.

• Take it outside and hold it in front of you in an open area where the wind is blowing.

• Look at the X on the bottom of the cup as it spins around. Count the number of times it spins around (revolutions) in 10 seconds. Use the table below to estimate the wind speed.

Working

• Or we can use Motorbike Speedometer to measure speed of cups which are being rotated by wind; this will give us speed of wind.

Working

Thank You