LI-COR addresses challenges in eddy covariance measurements
April 22, 2010 - Lincoln, NE
Measuring atmospheric trace gases at high frequency and precision can be difficult - even in the best of conditions. Additional factors of rain, snow, and extreme temperatures further compound the challenges of obtaining accurate data. Building on its more than 15 years of experience in researching and developing analyzers for eddy covariance measurement, LI-COR Biosciences introduces the LI-7200 Enclosed CO2/H20 Analyzer. The new LI-7200 is specifically designed to combine the benefits of open path and closed path analyzers. The LI-7200 is the newest edition to a family of open- and closed-path analyzers from LI-COR that are noted for their ability to be deployed in a variety of extreme locations.
"Our beta testers report that the LI-7200 improves the quality of the data because it is an enclosed weatherproof analyzer and its lightweight size gives the opportunity to mount the instrument closer to the actual sensing array, which reduces the amount of tube attenuation," says Bill Miller, LI-COR product manager. "The LI-7200 is optimized for the eddy covariance technique, it has the high speed and precision required for this method and does not require a temperature-controlled enclosure."
The LI-7200 provides the benefits of closed path instruments, such as continuous data collection in rain, snow, and fog; and the benefits of open path instruments, including low power requirements in a simple, integrated platform. The weatherproof sensor can be deployed at the top of a flux tower, with its intake close to the sonic anemometer measurement path making measurements without the complications that result from long tubing runs. The short (1 m), insulated intake tube attenuates water vapor minimally, while attenuating temperature fluctuations by 90-95%.
"The LI-7200 simplifies eddy covariance measurements by accepting signals from sonic anemometers and logging high-speed integrated data sets internally to a removable USB drive," says Miller. An optional 7200-101 flow module provides a weatherized solution for providing a controlled flow of air through the instrument.
For more information go to: www.licor.com/7200