Advantages
The LI-7200 CO2/H2O Analyzer is a high-performance non-dispersive infrared gas analyzer designed for demanding applications, such as eddy covariance measurements. It maximizes the strengths of traditional open-path and closed-path instruments.
Unlike closed-path instruments, the LI-7200 mounts on a flux tower or measurement platform right next to other measurement devices. It uses a short intake tube and an energy efficient flow module (optional) to draw sample air through the optical path. The tube can be as short as few centimeters or as long as many meters, but the optimal length is 0.5 m to 1 m. The 1 m intake tube provided with the instrument minimizes attenuation of CO2/H2O, while attenuating temperature by 90-95%. The remaining fluctuations are measured in the cell with two fast temperature sensors and a fast pressure sensor. This virtually eliminates the complications that result from long tubing runs.
Benefits of Closed Path
- Minimal data loss due to precipitation and icing
- No surface heating issues - fast cell temperature measurementes
- Possibility of automated calibrations on tower
- Minimal-to-negligible WPLH correction
- Possible to heat the system to prevent ice build up in extremely cold environments
Benefits of Open Path
- Good frequency response for both CO2 and H2O measurements
- Small and easily corrected flux attenuation in short intake tube
- Tool-free optical cell cleaning
- Low power requirements
- System simplicity, small size, light weight, and weatherproof design
LI-7200 CO2/H2O Analyzer
