Elliptic Anemometer™ II with wind vane

Why Elliptical? What is the advantage of elliptical cups? Elliptical wings of a WWII Spitfire gave it an aerodynamic advantage over German airplanes of the Luftwaffe while elliptical leading edge shape of wings for all of our most efficient transonic aircraft give them an efficiency edge. When it comes to anemometer design, it offers an aerodynamic advantage to a cup traveling upwind for 1/2 of its rotation while on the downwind side it offers a positive increase in drag over a circular or conical cup shape. Our Elliptic Anemometers also benefit from negligible over-speeding from non horizontal airflow, which is of major concern to wind speed measurement for wind energy applications as overspeed can amount to a 10% error with other anemometer designs.

Elliptic Anemometer™ Advantage


Elliptical cups have low drag and clean flow separation regions resulting in aerodynamically efficient, consistent and stable anemometer performance.

Spherical cups have unstable boundary layer separation regions resulting in aerodynamic instabilities affecting repeatability and consistency of wind speed measurement.

Conical cups have clean flow separation regions but large aerodynamic drag negatively affecting anemometer response time.

Elliptical cup provides a consistently longer moment arm for wind to push against, benefiting anemometer measurement consistency and response time.*

Circular cups have their center of pressure closer to the anemometer rotation axis, thus reducing wind’s moment arm to overcome anemometer inertia and friction effects.


Offered in 3 sensor flavors to accurately measure wind speed, wind direction, temperature, humidity and barometric pressure in one convenient and compact package. 3 sensor combinations: VDT*, VDT-H*, VDT-HP*

  • *V = Wind Speed (Velocity),
  • *D = Wind Direction
  • *T = Air Temperature
  • *H = Relative Humidity (%)
  • *P = Barometric Pressure


  • Wind Turbine Site Evaluation
  • Environmental studies
  • Weather monitoring for outdoor events
  • Wind Turbine control and monitoring
  • Rooftop wind and weather monitoring


  • Guaranteed resistance to 1/2 inch (12.7mm) hail stone damage
  • Highly reliable and electrostaticaly isolated electronics
  • Electronically adjustable high resolution Magnetic Wind Vane with continuous 360° 10bit (0.5deg) resolution
  • Remotely adjustable Wind Vane orientation for easy setup.
  • Lifetime maintenance free ceramic, ceramic hybrid, or plastic hybrid bearings to suit any application
  • Carbon Fiber Wind Vane mast for high survivability in high winds & gusts
  • Corrosion resistant Aluminum alloy ∅5/8 inch (16mm) and 14 inches (355mm) long mounting shaft for easy mounting, damage resistance and robustness
  • Temperature sensor integrated in all anemometer products
  • Humidity Sensor on -H & -HP anemometer versions
  • Barometric Pressure Sensor on -HP anemometer versions
  • Included Atmo free wind monitoring software with all products