Ever wondered what those weird-looking towers at weather stations are? Those are Anemometers and they serve a very important function.
Those who are well-versed in Greek can tell that Anemo has something to do with the wind since it means wind in Greek. Well, we are getting ahead of ourselves.
Anemometers are one of the most important inventions for the fields of Meteorology and Physics. Unfortunately, a lot of people don’t even know what this important instrument is, let alone what it does or where it’s used.
That is why we’ve set out to inform the masses about this revolutionary tool. So, without further ado, let’s dive right in.
What Is Anemometer?
So, we’ve sized up this device quite a bit. We’ve been singing praises about it for a good while now. You must be wondering, “What does an anemometer do? What makes this such a great invention?”
An anemometer is an instrument that measures wind speed and direction. Before its invention, there was no way to tell how fast the wind around you were blowing. You could tell the direction using a weather vane, but the speed was a mystery.
History Of The Anemometer
Despite the Greek name, this instrument was not invented in Ancient Greece. It was discovered much more recently. Around the year 1450, Italian inventor Leon Battista Alberti invented it. You may have heard his name before, as he is one of the pioneers of the Renaissance in Italy.
Another famous name attached to this device is that of Robert Hooke, who has often been falsely credited for its invention. However, he invented his take on the device in 1884.
The modern iteration of this device and the one you’ll find in most weather stations today is the one made by Irish physicist, Rev Dr. John Thomas Romney Robinson in 1845.
Initially, this wind meter only measured the speed of the wind. It was not until much later in 1991 that Derek Weston invented a way for it to tell the direction as well.
Today, it plays a vital role in any use cases where you need to find the speed of the wind in a particular area. But how does it even do that?
How Does Anemometer Work?
The way an anemometer works depends on the type of anemometer you are dealing with. There are many different kinds of anemometers and we’ll discuss them all briefly soon. To keep things simple, we’ll only cover the working principle of the most famous and widely used iterations in detail.
1. Mechanical Energy Working Principle
Remember how we told you that Rev Dr. John Thomas Romney Robinson’s version of this device is the one that caught on? Well, he invented the cup anemometer, and believe it or not, a lot of stations use his iteration to this day.
The mechanism of his version is fairly simple. It features a vertical pole with 3 or 4 horizontal arms attached to its top. On each arm is a cup. When the wind blows through these cups, the arms start moving. The collective movement of all the arms causes the entire anemometer to rotate.
Counting the number of turns over a set time can tell you the speed of the wind in that timeframe. Since windspeeds change so frequently, it is tough to get accurate results over long periods.
You can probably already tell another major flaw with this device. Sometimes, windspeeds simply aren’t fast enough for a complete or even partial rotation and that makes calculation difficult or inaccurate.
Along the same line of thought, a windmill style of the anemometer was developed but that never really caught on as the horizontal nature of a windmill makes it too susceptible to a change in wind direction.
2. Heat Energy Working Principle
In case you were sick of employing mechanical energy to measure the speed of the wind, you could use a hot-wire anemometer. This, as you can probably guess from the name, uses electrical energy to perform the same task.
A hot-wire anemometer is not a complicated device. It is essentially a wire that is constantly electrically heated. How does this help tell the speed of the wind?
Picture this, you’re out during a hot summer day and you’re feeling you are about to melt. What happens when a breeze comes your way? That’s right, it cools you down.
The hot-wire anemometer uses this exact mechanic in its feature. You see, the same that the wind keeps you from feeling too hot, it’s also going to stop the wire from getting too hot. The faster the wind gets, the better it gets at this purpose.
To keep the wire hot, more electrical energy needs to be channeled in. In other words, the faster the wind blows, the more heat energy or power you’ll need the hot-wire generates. This indirectly tells you the speed of the wind.
The issues with this method are also pretty obvious. The wind isn’t always fast enough to cool something down and that affects the accuracy of this device.
3. Other Working Principles
If you are looking for infallible and detailed results, you’ll have to opt for a laser doppler or an ultrasonic anemometer. We’ll cover them more thoroughly shortly.
There are a few other types of anemometers but they are seldom used.
Different Types Of Anemometer
You’ve already gotten a brief idea of the type of anemometers when we discussed the way each one of them worked. Let’s discuss the types in more detail & their pros and cons.
1. The Cup Anemometer
First off, we have the cup style. On the bright side, it is the cheapest version of an anemometer as it is the easiest to make. You could even make one at home.
The downside is the questionable accuracy. Furthermore, it is affected by environmental factors such as snowfall and hail. It won’t even work in freezing rain.
2. The Hot-wire Anemometer
Secondly, we have the hot-wire iteration, which is a bit more accurate. The con to this one is the fact that it is also affected by environmental factors which may cool it down faster.
3. The Laser Doppler And Ultrasonic Anemometer
The laser doppler anemometer uses laser light to calculate the speed of the wind. This is much more accurate and is not affected by environmental factors at all. The best part is that- they are a lot faster than the previous devices as well.
The issue is, it is a lot more expensive. The same goes for an ultrasonic anemometer which uses sound waves.
4. Other Anemometers
The less famous cousins of the aforementioned anemometers include tube, dissipation, and ping pong style versions. They are not used very often. Speaking of which, where are anemometers used?
Most Common Applications Of An Anemometer
As we’ve mentioned before, you’ll likely find one of these at your local weather station, and there’s a good reason for that. The wind is one of the best indicators of the weather for the near future.
1. Weather Forecasting
Finding out the speed of this wind can be vital in weather forecasts. The change in the velocity of wind can indicate a future rise or fall in temperature or some cases, even a storm.
2. Flight Planning
As it can warn you about dangers like a storm, you can rely on an anemometer to check if the weather conditions are alright for flying. Pilots are one of the most avid users of this technology.
Lastly, these devices are also used in the development of the planes that these pilots will be flying. Accurately determining the wind velocity can help a lot with perfecting the aerodynamics of an aircraft.
Frequently Asked Questions
1. Why Are Anenometers Important?
Anemometers can accurately tell you the speed of the wind and as we’ve covered thoroughly already, this velocity helps in meteorological and aeronautical purposes.
2. Is There Any Other Way To Tell The Speed Of The Wind?
You could also use a barometer to calculate the pressure caused by the wind and calculate wind speed from there. However, this is a very lengthy and complicated process.
3. Can I Make My Anemometer?
Yes. The cup anemometer is so simple that you can build it right now out of cardboard. Getting accurate results from your DIY project will be the only hard part of the project.
4. Can An Anemometer Break?
Certainly. That is why proper installation is very important. These devices can cost a lot and replacing them can sometimes cost a fortune.
There you have it. A complete guide on what anemometer is, what they do, and where they are used. We hope we have helped you to gather insight on Anemometer. Such nifty devices help so many scientists out there.