Canadian meteorologist John Patterson developed the first 3-cup anemometer in 1926. Today, we celebrate the 3-cup anemometer’s 95th anniversary!
This post marks the first of a multi-part Meet & Greet series on meteorological equipment available here at Energy Canvas. Today, we are excited to kick-start the series with the four main types of anemometers we sell!
Anemometers have one job: measure wind speed, yet they can come in all sorts of unique designs. With each type of anemometer having its own set of features, some projects may only need one type, while others might benefit from using a combination of two or more. It’s all about finding relevant solutions!
One way to categorize anemometers is whether they depend on moving parts to measure wind speed. For example, vertical-axis cup anemometers and propeller anemometers rely on moving parts, whereas 2D and 3D ultrasonic anemometers do not. Another way to categorize them is whether they can measure only scalar wind speed (“how fast is the wind blowing?”), or if they can measure vector wind velocity (“how fast and from where is the wind blowing?”). In addition, anemometers can be differentiated by whether they can be heated.
Vertical-axis cup anemometers are probably the most common type. Our Thies First Class Advanced II is a perfect example of this. Construction-wise, they comprise of a few cup-shaped structures that catch any horizontal wind coming at them. These cups are attached to a vertical shaft to enable a spinning motion. The greater the wind speed, the faster the cups spin, and thereby the more revolutions per minute (rpm). This type of anemometer measures scalar wind speed and is unable to register directional information within the horizontal plane.
Propeller anemometers like our 27106T model measure wind velocity for airflow that passes parallel to the orientation of the axis. For example, for a project on hilly terrain, propeller anemometers are installed with the axis pointing vertically to measure the vertical component of wind flowing diagonally up or down the hill. These function and record data in a similar way to the cup anemometers and are a complimentary tool in the wind resource measurement toolkit.
Some of the potential issues with anemometers that rely on moving parts to function include performance under icing conditions and inertia distorting the accuracy of measuring gusty or turbulent winds. Furthermore, the constant friction between structural parts could cause wear and tear, affecting longevity of the equipment.
This is where ultrasonic anemometers bring something different to the wind measuring toolkit.
Ultrasonic anemometers are another type of wind velocity anemometer, but they operate using a totally different technology since they have no moving parts. This type of anemometer uses stationary prong-like structures, called “arms,” that send out ultrasonic pulses to measure the wind speed. Immobile sensors avoid the risk of moving parts freezing and slowing during icing events, which translates to better quality data even for projects in cold environments. They are also a lot less affected by inertia, so gusty and turbulent winds are represented more accurately.
As seen with our Ultrasonic Anemometer Thies 2D series, the sensor heads at the tip of each arm line up on a horizontal plane, so these would be great for recording horizontal wind velocity. Building upon that technology are their 3D counterparts, such as our Ultrasonic Anemometer Thies 3D. These anemometers have an additional set of arms and sensor heads right above, which enables communication between the bottom and top sensor heads. Of course, these come in heated and ice-free versions to further improve data availability in colder climes.
Which type of anemometer is the best fit for your project?
Contact us to discuss how we can help you get the right equipment for what you’re working on!