C-3 Anemometer

The KRC3 Anemometer is an improved version of the popular three-cup design used in wind assessments for decades, manufactured to precise industry standards. The Model KRC3 rotor is made of tough polycarbonate for exceptional durability and reliability. The Model C3 sensor base is also made of rugged polycarbonate, making it more resistant to damage during installation.

Manufactured with exceptional quality control — all units are tested mechanically and electronically before shipping. The KRC3 is made entirely of Lexan, a strong plastic that makes the Second Wind anemometer less likely to break during installation. Its distinctive blue vinyl boot shields wiring for long-term performance. Additionally, it is manufactured to meet new standards and is RoHS-compliant — no toxic metals. All models are individually laser-engraved with serial number and date code, simplifying tracking and data analysis.

Ordering Information and Calibration Options

MEASNET Calibrated KRC3 Anemometer

The MEASNET Calibrated C3 anemometer is MEASNET calibrated in Denmark and includes a certificate of calibration. Part #983

MIT Calibrated KRC3 Anemometer

Our Model C3C anemometer has been calibrated at the highly respected Massachusetts Institute of Technology's Wright Brothers wind tunnel. Part #982

Uncalibrated KRC3 Anemometer

Customers with their own calibration capability can choose this option. Part #981

Specifications

• Conical cups measure 51 mm (2 inches) in diameter
• Rotor diameter is 190 mm (7.5 inches)
• Standard AC output, frequency proportional to cup rotational speed
• Shielded AC pickup coil, 4100 turns of #41 wire
• Four-pole Indox 1 magnet rotates with the cup assembly
• Fully hardened beryllium-copper shaft running in self-lubricating modified Teflon bearings, with protective boot to make the system dirt and water resistant
• Rated bearing PV (pressure-velocity) factor is 20,000
  • At 15 mph PV is approx. 500.
  • At 100 mph PV is approx. 2,000.
• Rotor assembly moment of inertia = 68 x 10–6 S-ft2 (or 92.2 x 10–6 kg-m2)
• Distance constant = 10 feet (3.0 meters)
• Transfer Function: m/s = (Hz x 0.766) + 0.324
     [miles per hour = (Hz x 1.714) + 0.725]
• Accuracy: within 0.1 m/s (0.2 mph) for the range 5 m/s to 25 m/s (11 mph to 55 mph)
• Includes rubber boot.