The CSAT3 is a three-dimensional sonic anemometer. It measures wind speed and the speed of sound on three nonorthogonal axes. From these measurements, orthogonal wind speed and sonic temperature can be computed.
The CSAT is used in eddy covariance applications to measure the turbulent fluctuations of horizontal and vertical wind. From the turbulent wind fluctuations, momentum flux and friction velocity can be calculated. The CSAT3 can also be used to measure average horizontal wind speed and direction.
Features
Measures turbulent fluctuations of horizontal and vertical wind
Measures wind speed and the speed of sound on three nonorthogonal axes.
Provides upper and lower transducers that are separated by a vertical distance of 10 cm and are oriented 60 degrees from horizontal.
Typically used with fine wire thermocouples and LI7500 (or KH20) in Eddy covariance systems
No moving parts
Specifications
Measurements
Outputs: ux, uy, uz, c (ux, uy, uz are wind components referenced to the anemometer axes; c is speed of sound)
Speed of Sound: Determined from three acoustic paths; corrected for crosswind effects
Measurement Rate: programmable from 1 to 60 Hz, instantaneous measurements; two over-sampled modes are block averaged to either 20 Hz or 10 Hz
Measurement Resolution: ux, uy is 1 mm/s rms; uz is 0.5 mm/s rms; c is 15 mm/s (0.025°C) rms; values are for instantaneous measurements made on a constant signal; noise is not affected by sample rate
Accuracy (assumes -30° to +50°C range; wind speeds <30 m/s; wind angles between ±170°)
Offset Error: <±4.0 cm/s (ux, uy); <±2.0 cm/s (uz)
Gain Error: <±2% of reading (wind vector within ±5° of horizontal); <±3% of reading (wind vector within ±10° of horizontal); <±6% of reading (wind vector within ±20° of horizontal)
Rain: Innovative ultrasonic signal processing and user-installable wicks considerably improve the performance of the anemometer under all rain events
Output Signals
Digital SDM: CSI 33.3 k baud serial interface
for datalogger/sensor communication. Data type is 2-byte integer per output plus 2-byte diagnostic
Digital RS-232
Baud Rate: 9600, 19200 bps
Data Type: 2-byte integer per output plus 2-byte diagnostic
Analog
Number of Outputs: 4
Voltage Range: ±5 V
Number of Bits: 12
Reporting Range
SDM and RS-232 Digital Outputs
Full Scale Wind: ±65.535 m/s autoranging between four ranges; least significant bit is 0.25 to 2 mm/s
Speed of Sound: 300 to 366 m/s (-50° to +60°C); least significant bit is 1 mm/s (0.002°C)
Analog Outputs: see chart in product brochure
Producing Area:USA