The eddy covariance (EC) flux system is used for long-term monitoring of atmospheric-biosphere exchanges of carbon dioxide, water vapor, heat, and momentum. A complete system consists of a closed-path gas analyzer (EC155 closed-path gas analyzer), sonic anemometer (CSAT3A sonic anemometer), data logger (CR6 datalogger), sample pump, and accommodations for a   CDM-A116 allowing for additional sensors. The gas analyzer’s intake design and small sample cell volume (5.9 mL) provide excellent frequency response (4.3 Hz cutoff frequency) with low total system power (12 W).

Gas flux is a free CR Basic program that enables a data logger to report fully corrected fluxes of CO2, latent heat (H2O), sensible heat, and momentum from a Buraq Integrated Solutions open-path and closed-path eddy-covariance (EC) system. Final fluxes are processed from raw high frequency time series data by applying commonly used corrections found in scientific literature.

Gas flux has been tested at several stations in various environments, including irrigated alfalfa, grassland, maize, open water, forest, and desert. The results have shown good agreement with fluxes processed using traditional PC-based software applications

Benefits and Features

  • New conformal coating helps protect sonic transducers in corrosive environments
  • Expandable, mid-level system with CR6 datalogger processing power
  • Suitable for sites with many sensors and either a short or tall tower
  • Simple design for easier troubleshooting

Eddy-Covariance Measurements

CO2 and H2O are measured with an EC155 Closed-Path Gas Analyzer. Three-dimensional wind speed and sonic air temperature is measured with a CSAT3A sonic anemometer head.


Operating temperature Range-30° to +50°C
Input voltage range10.5 to 16.0 Vdc

35 W (maximum, at cold startup)

12 W (typical)

System enclosure

Dimensions54 x 44.5 x 29.7 cm (21.3 x 17.5 x11.7 in.)

14.6 kg (32.2 lb.) with optional

CDM-A116 module

 13.72 kg (30.25 lb.)

Pump module

Inlet connector3/8-in. Swagelok
Pressure sensor range15 to 115 kPa
Pumping speed

3 to 9 LPM (automatically

controlled at the set point,

typically, 7 LPM)