H2O/CO2 Open Path Analyzer

The LI-7500 from LI-COR is an open-path infrared gas analyzer (IRGA) used to measure water vapor and carbon dioxide fluctuations.  In combination with a 3D sonic anemometer it measures the fluxes of these quantites.  The older models that EOL has are known to have errors especially in cold conditions due to the ~12W of heating used by this sensor to keep the optics and internal volume moisture free.  ISFS now uses the Campbell EC-150 to make this measurement.