- 1
- Cup wheel assembly
- 2
- Sensor shaft
- 3
- Lower body
WAA151 is a fast-response, low-threshold anemometer. Three lightweight, conical cups mounted on the cup wheel provide a linear response rate over the entire operating range, up to 75 m/s (168 mph).
A wind-rotated chopper disc attached to the shaft of the cup generates a pulse output from a phototransistor in the base of the sensor. The output pulse rate is directly proportional to wind speed.
The heating element in the shaft tunnel keeps the temperature of the bearings above the freezing level in cold climates. The nominal heating power is 10 W. Vaisala recommends that you use a thermostat switch in the cross-arm for switching the heating power on below +4 °C (+39 °F).