What are anemometers?
You have probably learned about anemometers since you were a kid. Well, the anemometers are instruments used in the measure of wind speed in an area. It is a crucial component that should never miss in a weather station. Being crucial means that you have to choose it correctly at all times. Making a wrong move could land you with the incorrect anemometer for your needs. It can be handheld or mounted type of anemometer. Below, we get to look at the different types of anemometers to consider buying today.
Most anemometers you might have seen would be the cup anemometers. They are quite common as compared to the other models. The cup anemometer would often consist of 3 or 4 cups, which rotate when the wind hits them. The cups can be based on various applications. Whenever the wind blows, the cups rotate and the read switch sensor will measure the rotations. It is from the rotations that they can be converted into wind velocity.
The cups are made to be highly reliable and rugged so that taking the measurements should not be a problem. The common problem is that the rotating parts will often wear out with time.
- It does not need to be pointed in the direction of the wind speed to work
- The cups are made to be highly durable and reliable
- The starting velocity is often high
- It often fails due to the icing effect
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The vane anemometers they work on the same principle as the cup anemometers with a slight variation. In this type of anemometer, the sensors are designed to look like a windmill or turbine. This means that the anemometer has to be parallel to wind direction for it to spin. In this case, it can only spin in the horizontal axis.
The vane anemometers are often preferred as they are made to be more rugged and durable than most types of anemometers. The ruggedness means that they can handle higher wind speeds occurring in an area.
- They are suitable for harsh environments
- The durability of such anemometer is very impressive than other models
- They are designed to handle higher wind speeds
- It has to be pointed towards the wind source for better accuracy
- If the anemometer has smaller vanes, it will often have a high starting speed
Hot Wire Anemometers
The hot wire anemometers operate on a different principle. The hot wire anemometers will not have any form or cups, but rather a heated thin wire. The wire is electrically heated to a certain temperature and it gets cooled when wind flows over it. The current is needed to keep the hot wire at the desired temperature. The change in temperature is measured based on the passing wind. It is from the heat loss that the velocity is calculated and then displayed to the user.
Since there are no rotating parts, then the equipment should be able to last for longer. This is when comparing it to the cup and vane anemometers. This type of anemometer will provide you with high accuracy and quick response too.
- It comes with low starting threshold
- It has no rotating parts meaning it can last longer
- It has a quick response to provide better accuracy readings
- Not effective in areas with rapid temperature fluctuations
- It is not suitable for dirty environment
Pitot Tube Anemometers
This now uses a totally different way of measuring the wind speed. It does first measure the wind pressure, which is later on converted to velocity. This anemometer has a pitot tube and a static tube. The pitot tube will measure the incoming air pressure and the static tube will measure the wind flow static pressure. It is from these values that the wind velocity is calculated using the Bernoulli’s equation.
With its design, the anemometer is seen to handle high wind velocity. With no rotating or moving parts, it does not need regular maintenance. Its design also offers a quick response system to the wind velocity.
- Can easily handle high wind velocities
- It comes with a quick response system
- It does not wear out easily as it has no moving parts
- Not suitable for areas with low wind velocity
- Not recommended in scenarios with fluctuating wind speeds
These are the most advanced anemometers you will ever get on the market today. They are designed to use the ultrasonic sound waves to measure the wind velocity. That is not something common today. The wind speed is measured in terms of the time of flight for the sonic pulses between the various transducers.
It does not have the common problem of icing effect as compared to the cup anemometer. It is also built to be weather resistant so that it can be used in various weather conditions.
As much as it has many benefits, it is very rare, making it more expensive to repair as compared to other types of anemometers.
- It is designed to be weather resistant, thus lasts longer
- It has no rotating parts that could easily wear it out
- It is more expensive as compared to the other types of anemometers
- The birds might perch on the probes causing false wind gusts
The next time you go looking for a great anemometer, you now have a chance to choose the correct one. You also need to keep in mind things like response to wind speed, accuracy ratings by other users, the construction material, and the size too. These are still important factors for buying an anemometer.