Anemometer – ET-40AC

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This AC frequency 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 anemometer 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 anemometer 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.

Contact us or call us at (413) 835-5387 with questions about your application.

Features

  • Elegant Design
  • Dirt and Water Resistant
  • Corrosion Resistant Construction
  • Modified Teflon bearing system
  • Completely Self-Powered with self-contained alternator
  • One Piece Molded Cup Assembly

Applications

  • Research Measurements
  • Engineering Studies on wind effects on structures
  • Control Anemometer for new or existing wind warning devices
  • Wind Resource Management

Specifications

  • Accuracy
    • 3 m/s to 25 m/s (+/- 0.1 m/s)
      • < 3 m/s (+/- 0.2 m/s)
      • > 25 m/s (+/- 1% of reading)
    • 7 MPH to 55 MPH (+/- 0.2 MPH)
  • Threshold
    • Starting – less than 0.75 m/s (1.75 MPH)
    • Cup Distance Constant – 3.0m (10 ft.) 63% recovery
  • Materials
    • Rotor and Housing Body – Injection molded black polycarbonate
    • Shaft – Beryllium  Copper (Fully Hardened)
    • Bearing – Modified Teflon, self-lubricating
    • Rated PV factor of 20,000 (at 6.7 m/s or 15 MPH, PV is approx. 500; at 45 m/s or 100 MPH 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 pole
  • Weight
    • 0.1 kg (0.2 lbs.)
  • Dimensions
    • 3-Cup Conical Cross Section – 51 mm (2 in.) diameter
    • Swept Diameter of Rotor – 190 mm (7.5 in.)
    • Overall Height – 81 mm. (3.2 in.)
    • Moment of Inertia of rotor assembly – 68 x 10-6 S – ft^2
  • Electrical
    • Sine Wave Output changes linearly with Wind Speed
    • 60 Hz = 102 MPH
    • Voltage Output (typical)
      • @ 1 Hz.  100 mV p-p
      • @ 30 Hz.  >2V p-p
  • Transfer Function
    • MPH = (Hz x 1.698) + 0.708
    • m/s = (Hz x 0.758) + 0.316
  • Environmental 
    • Operating Temperature – -55C to 65C (-67F to 150F)
    • Operating Humidity – 0-100% RH
    • Gust Survival Speed – 232 MPH
    • Lifespan – 3-5 years under normal circumstances