An anemometer is used for measuring the wind velocity.
There are various types of anemometers; some are very common, while others are rare.
In this article, we are gonna introduce you to some of the finest and most commonly used anemometers available on the market.
So, shall we get started?
Let's presume that your answer is yes.
Cup anemometers are certainly the most common type of anemometers. I’m sure you have also seen one at some point in your life.
There are mainly two reasons behind their popularity:
Simplicity and durability.
It mostly consists of 4 cups, which are mounted on 4 horizontal arms, which themselves are mounted on a vertical pole.
When the wind hits the anemometers the cups begin to rotate. The faster the cups move the faster is the wind speed.
There is a read switch sensor to measure the rotations of cups, which subsequently gets converted into the velocity.
The cups are sturdy and stable. Thus, it should have no problems with taking measurements in bad weather.
- You won’t have to point it towards the direction of the wind to make it work.
- The cups are well-built and capable of enduring rough weather
- Vulnerable to icing effect.
- Its starting velocity is often pretty high
Hot Wire Anemometers
The mechanism of hot wire anemometers is completely unique.
It uses an extremely thin wire, which is electrically heated up to a temperature which is higher than the ambient. The wire then loses temperature and gets cooled as the air flows past it.
Then the current required to maintain the preferred temperature is measured. Finally, the velocity of the wind is then determined by the loss of heat.
Hot wire anemometer has a quick response and delivers precise readings of the wind velocity.
It will also last longer as there are no rotating parts involved.
- Lasts longer than other anemometers
- Hot wire anemometers consist low starting threshold
- Provides error-free reading
- Ineffective in areas where the temperature fluctuates quickly
- It can get damaged by the dirt
Sonic anemometer employs the ultrasonic sound waves to calculate the wind velocity.
The mechanism of the sonic anemometer is rather advanced compared to the other anemometers.
It uses the time of flight taken by sonic pulses between several transducers to reckon the speed of the wind.
Moreover, this device is weather resistant and suitable for working in severe weather condition. As the device is internally heated, icing can have no effect on it.
Although the device comes with numerous advantages, there's a catch:
It's damn expensive.
Due to being more expensive than others, it’s pretty rare.
- Not affected by icing
- Weather resistant and suitable for extreme weathers
- Very expensive
- Birds may sit on the probes resulting in false wind gusts.
Its mechanism is pretty similar to the cup anemometer.
There’s anobvious difference between them:
The windmill anemometers look like a windmill.
For this reason, the anemometer has to be parallel to the direction of the wind in order to make the device rotate. However, it will rotate only on the horizontal axis.
Most of the windmill anemometers are made ruggedly; hence it lasts longer than most of the anemometers.
- Capable of handling high wind speeds
- Lasts longer
- Made for the heavy-duty purpose
- You will need to point the unit towards the direction of the wind to get accurate readings
- The rotating parts of the unit may deteriorate over time
- If the vanes of your anemometer are small, then it can sometimes cause high starting speed.
Pitot Tube Anemometers
The pitot tube anemometers use a unique process for measuring the wind velocity.
First, it measures the pressure of the wind. Thenit converts the pressure of the wind into the velocity of the wind.
The anemometer comes with two different types of tubes; static tube and pitot tube.
The incoming air pressure will be measured by the pitot tube, whereas the static tube is responsible for measuring the static pressure in the flow of the wind.
Afterward, the wind velocity will be determined from these values by using the Bernoulli’s equation.
High wind speed isn’t a problem for pitot tube as it handles it quite efficiently.
In addition, pitot tube anemometers offer a quick response.
- Suitable for high wind speeds
- Provides a quick response
- As it includes no rotating parts, it doesn't deteriorate easily
- Ill-suited for low wind velocity areas
- Inappropriate for fluctuating wind speeds
To conclude, an anemometer is a vital part of the weather station.
If you’re going to buy one, make sure that it’s suitable for your area. Cheerio!