Field Instrumentation
The field instrumentation for acoustic measurements was selected to meet IEC 61400-11, Wind Turbines - Part 11: Acoustic Noise Measurement Techniques and to record the frequency range of 0.1 Hz to 20 kHz. The instrumentation is as follows:
Microphones
- B&K 4191 with 2669L preamplifier
- Audible range with flat frequency response from 5 Hz to 16 kHz
- B&K 4193 with 2669L preamplifier and UC0211 adapter for low frequency use
- Infrasound and low frequency range with flat frequency response from .1 Hz to 5 k Hz
- B&K Nexus 2690 amplifier and power supply
- B&K UA-0237 90mm diameter primary windscreen
- 20 inch diameter secondary windscreen following IEC 61400-11 guidelines
- INFILTEC microbarometer INFRA20
- Infrasound monitor, frequency range from .05 Hz to 20 Hz
Met One portable meteorological station (10 feet)
- Wind speed
- Wind direction
- Temperature
- Barometric pressure
- Relative humidity
Mobile LiDAR
- Portable measurement device for wind speed and direction at 10 elevations between 40m and 200m. Used for calculating wind shear.
GPS Receiver
- Distance and heading from turbine
Eolos Meteorlogical Tower and Turbine Supervisory Control and Data Acquisition (SCADA)
- 130 meter meterological tower with 10 measurement elevations
- 2.5 MW Clipper Liberty wind turbine with continuously logged SCADA data
Calibration Facilities
Atmospheric Boundary Layer Wind Tunnel at the St. Anthony Falls Laboratory (SAFL). This facility may be used to measure the the effects of wind noise with secondary windscreens.
Semi-Anechoic Room at the Center for Applied & Translational Sensory Science (CATSS), affiliated with the Speech-Langauge-Hearing Sciences (SLHS). This facility may be used to measure attenuation of wind screens.
