Precipitation can block the infrared beam of an open-path IRGA—primarily through accumulation on the windows and by falling through the measurement path. The EC155 is a closed-path IRGA that is protected from rainfall by taking its measurements within a sample cell assembly. Older EC155 models (serial numbers less than 2000) have a heated intake assembly with a rain diverter to prevent precipitation from entering the sample cell. Newer EC155 models (serial numbers 2000 and greater) have a heated inlet and vortex intake (U.S. Pat. No. 9,217,692), which significantly improve performance during precipitation events and in conditions of high particulate concentrations, such as dust storms. However, measurements from sonic anemometers can also be affected by rainfall, especially if droplets accumulate on transducer faces. Therefore, it is important to continue monitoring data during rainfall events to ensure quality measurements are included in final calculations of flux.