CSAT3

3-D Sonic Anemometer

CSAT3

Retired

3-D Sonic Anemometer

Pricing

Model:: CSAT3
Item Number:: R_8900
Warranty:: 1 year

Overview

RMA_CSAT3 3-D Sonic Anemometer, 7.6m (25ft) Cables

The CSAT3 is a three-dimensional sonic anemometer that measures three orthogonal wind components and the speed of sound. In eddy covariance systems, it can measure the turbulent fluctuations of horizontal and vertical wind. These measurements are then used to calculate momentum flux and friction velocity. This sonic anemometer can also provide average horizontal wind speed and direction measurements. The CSAT3 comes with 25 ft cables.

Key Advantages

Precision Measurements
Best instrument for flux and
other high-level turbulence
research projects

Technical Description

The CSAT3 has a 10 cm vertical measurement path and operates in a pulsed acoustic mode. The three orthogonal wind components (u_x, u_y, u_z) and the speed of sound (c) are measured and output at a maximum rate of 60 Hz. Analog outputs and two types of digital outputs are provided.

Measurements can be triggered from from the CSAT3’s internal clock, the PC-generated RS-232 command, or the data logger’s SDM command. The SDM protocol supports a group trigger for synchronizing multiple CSAT3s.

The FW05 fine wire thermocouple (12.7 μm diameter) is available as an option for fast response temperature measurements.

Benefits

Provides precision turbulence measurements with minimal flow distortion
FW05 fine wire thermocouple (12.7 μm diameter) is available as an option for fast response temperature measurements
Withstands exposure to harsh weather conditions
Measurements can be used to calculate momentum flux and friction velocity
Compatible with most Campbell Scientific data loggers

Specifications

Measurement Path Length: 10.0 cm
(3.94 in.) vertical
Measurement Path Length: 5.8 cm
(2.28 in.) horizontal
Path Angle from Horizontal: 60°
Construction: Sealed sonic transducers and electronics
Anemometer Head Materials: Stainless-steel tubing
Electronics Box Materials: Cast aluminum
Operating Temperature Range: -30° to +50°C
Voltage Supply: 10 to 16 Vdc
Current: 200 mA
(60 Hz measurement rate)
Current: 100 mA
(20 Hz measurement rate)
Digital SDM Output Signal: CSI 33.3 k baud serial interface for data logger/sensor communication.
(Data type is 2-byte integer per output plus 2-byte diagnostic.)
Support Arm Diameter: 1.59 cm
(0.63 in.)
Transducer Diameter: 0.64 cm
(0.25 in.)
Transducer Mounting Fingers Diameter: 0.84 cm
(0.33 in.)
Cable Length: 7.62 m
(25 ft)
Anemometer Head Dimensions: 47.3 x 42.4 cm
(18.6 x 16.7 in.)
Anemometer Head Weight: 1.7 kg
(3.7 lb)
Electronics Box Dimensions: 26 x 16 x 9 cm
(10.24 x 6.3 x 3.54 in.)
Electronics Box Weight: 3.8 kg
(8.4 lb)

Measurements

Outputs: u_x, u_y, u_z, c

(u_x, u_y, u_z 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: Resolution values are for instantaneous measurements made on a constant signal; noise is not affected by sample rate.
Measurement Resolution: 1 mm/s rms
(u_x, u_y)
Measurement Resolution: 0.5 mm/s rms
(u_z)
Measurement Resolution: 15 mm/s (0.025°C) rms
(c)
Measurement Resolution: 0.06° rms
(wind direction)
Offset Error: Offset error and gain error values assume the -30° to +50°C range, wind speeds of < 30 m/s, and wind angles between ±170°.
Offset Error: < ±8.0 cm/s
(u_x, u_y)
Offset Error: < ±4.0 cm/s
(u_z)
Gain Error: Offset error and gain error values assume the -30° to +50°C range, wind speeds of < 30 m/s, and wind angles between ±170°.
Gain Error: < ±2% of reading
(wind vector within ±5° of horizontal)
Gain Error: < ±3% of reading
(wind vector within ±10° of horizontal)
Gain Error: < ±6% of reading
(wind vector within ±20° of horizontal)
Wind Direction Accuracy: ±0.7° at 1 m/s
(for horizontal wind)
Rain: Innovative ultrasonic signal processing and user-installable wicks considerably improve the performance of the anemometer under all rain events.

Digital RS-232 Output Signal

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

SDM & RS-232 Digital Outputs Reporting Range

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).