Anemometer - ET-40RS

Regular price $95.00

This wind sensor (i.e. anemometer) is an improved version of the popular three-cup design that has been used in wind assessments for decades, manufactured to precise industry standards. The rotor is made of tough polycarbonate for exceptional durability and reliability. The sensor base is also made of rugged polycarbonate, making it more resistant to damage during installation and use.

Manufactured in the USA with exceptional quality control—all units are tested mechanically and electronically before shipping. The sensor is made entirely of Lexan, a strong plastic that makes the anemometer less likely to break during installation and operation. Its distinctive vinyl boot shields wiring for long-term performance. Additionally, it is manufactured to meet new standards and is RoHS-compliant— no toxic metals.

Note: The ET-40AC does not come with the stub mount. The stub mount can be purchased separately here.


  • Anemometer for wind resource assessment instrumentation
  • Research measurements in environmental studies
  • Engineering studies on wind effects on bridges, skyscrapers
  • Control anemometer for new or existing wind warning devices


  • Very simple, RoHS compliant, elegantly engineered construction
  • Dirt and water resistant, modified Teflon bearing system
  • All corrosion resistant materials
  • All three cups molded in one piece for repeatable performance
  • Professional qualities at a minimum price


  • Threshold: Starting threshold – 0.75 m/s (1.75 mph) Cup distance constant (63% recovery) -3.0m (10 ft.)
  • Materials : Cups are one piece injection molded black polycarbonate (Lexan). Body housing is blac ABS plastic; Shaft is fully hardened beryllium copper; Modified self-lubricating teflon bearings. Rated Pv factor of 20,000 (at 15 mph, Pv is approx. 500; at 100 mpg Pv is approx. 2,000) Upper Bearing is centered in the plane of cup thrust for optimal loading. Permanent magnet Indox 1, 25 mm (1 in.) diameter., 13 mm (0.5 in.) long, 4 poles
  • Weight: 0.1 kg. (0.2 lb.)
  • Dimensions: 3 cups conical cross-section – 51 mm (2 in.) diameter.
  • Swept diameter of rotor- 190 mm. (7.5 in.); Overall height – 51 mm. (2 in.); Moment of Inertia of rotor assembly = 68×10-6 S- ft2
  • Mounting: Using cotter pin on a 13 mm. (0.5 in.) diameter mast with a #35 hole 11 mm (.35 in) from the top
  • Electrical: Reed Switch: Maximum Voltage 10VDC; Maximum Current 10 mA; Lifetime 10^9 cycles.
  • Output signal: Contact transfer rate varies linearly with wind speed. 120 contact transfers per second at 102.5 mph.
  • Environmental: Operating Temperature: -40 to 60oC (-40 to 150oF); Operating humidity range 0 to 100% RH Gust Survival Speed: 214 mph