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.