CSAT3A 3-D Sonic Anemometer, Head Only
Precision Measurements
Best instrument for flux and other high-level turbulence research projects
weather applications water applications energy applications gas flux & turbulence applications infrastructure applications soil applications

Overview

The CSAT3A sonic anemometer head is similar to the sensor head from the CSAT3 sonic anemometer, but its cable is modified to connect to the EC100 electronics. It is used as part of the EC150 open-path analyzer and the CPEC200 closed-path eddy-covariance system.

Read More

Benefits and Features

  • Can be combined with EC150 or EC155 gas analyzers for open-path or closed-path eddy-covariance applications (OPEC or CPEC)

Images

Detailed Description

The CSAT3A is an optional component of an EC150 open-path or EC155 closed-path CO2/H2O gas analyzer. It attaches to a common mounting bracket and connects to the gas analyzer's EC100 electronics module.

Specifications

Measurement Path Length
  • 10.0 cm (3.94 in.) vertical
  • 5.8 cm (2.3 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)
  • 100 mA (20 Hz measurement rate)
Digital SDM Output Signal CSI 33.3 k baud serial interface for datalogger/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 Arm Diameter 0.84 cm (0.33 in.)
Anemometer Head Dimensions 47.3 x 42.4 cm (18.6 x 16.7 in.)
Anemometer Head Weight 1.7 kg (3.7 lb)

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
  • Resolution values are for instantaneous measurements made on a constant signal; noise is not affected by sample rate.
  • 1 mm/s rms (ux, uy)
  • 0.5 mm/s rms (uz)
  • 15 mm/s (0.025°C) rms (c)
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°.
  • < ±8.0 cm/s (ux, uy)
  • < ±4.0 cm/s (uz)
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°.
  • < ±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.

Digital USB and RS-485 Output Signal

Baud Rate 230400 bps (maximum)
Data Type Comma-delimited ASCII

SDM, USB, & RS-485 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).

Compatibility

Datalogger Considerations

Compatible Dataloggers

CR200(X) Series CR800/CR850 CR1000 CR3000 CR5000 CR7X CR9000X

Frequently Asked Questions

Number of FAQs related to CSAT3A: 23

Expand AllCollapse All

  1. No. The CSAT3 is a sensor. Time stamps are assigned to the CSAT3 data by the data acquisition system—typically a Campbell Scientific datalogger or PC.

  2. Ultrasonic anemometers are unable to make measurements if the sonic path is blocked. The path may become blocked by water that puddles on the lower transducer face or droplets that hang from the upper transducers.

  3. The CSAT3 is compatible with three output signals: analog, RS-232, and Synchronous Device for Measurement (SDM). The CSAT3 can be interfaced to any data acquisition system that is compatible with analog measurements or RS-232 serial communications. SDM is used with Campbell Scientific dataloggers.

  4. Campbell Scientific does not offer any mounting booms or hardware that enable easy and frequent positioning of the CSAT3 sensor head. This type of hardware must be provided by the user.

  5. Yes. The CSAT3 measurement frequency can be changed by the user. It is set by the Execution Parameter. This parameter is described in detail in the CSAT3 instruction manual in the “Datalogger Instruction Parameters” section, as well as in the “CSAT3 RS-232 Commands” section of Appendix B.

  6. The CSAT3, like other sonic anemometers, measures wind speed along the sonic path using ultrasonic signals. If the salt spray blocks the sonic path, the CSAT3 will not be able to make measurements. The same is true if a thick layer of salt is deposited on the transducer faces.

  7. Yes. If the matching layer is damaged or missing, return the CSAT3 to the factory for repair. Follow the steps listed on our Repair and Calibration page to request a returned material authorization (RMA) number. 

  8. The CSAT3 measures three-dimensional wind in a right-handed Cartesian coordinate system. From these measurements, use trigonometry to compute the wind flow angle, horizontal angle, and wind speed.

  9. No. The CSAT3 does not report time with the wind measurements. A time stamp will be assigned to the wind data by the data acquisition system—either a datalogger or a PC.

  10. The CSAT3 offset specification is ±8 cm/s. Therefore, it cannot be used in an application where the expected wind speed is in the range of ±5 cm/s.

Case Studies

Canada: Forest Carbon Sequestration
Forest habitats contribute more than any other terrestrial biome to carbon cycles and processes. It......read more
Alaska: Eddy Covariance
Scientists and land-use managers have long recognized the importance of forest lands for their role......read more