Correcting Air Temperature Measurements from a Radiation-Exposed Sensor.

Despite seeming simplicity, air temperature is one of the most difficult environmental parameters to measure accurately.  Current best practice includes housing the air temperature sensor in a radiation shield that is either passively ventilated or actively aspirated.  Due to design constraints, the air temperature sensor in the new MA-4100 MicroEnvironment Monitor cannot be fully shielded from solar radiation.  However, since the MA-4100 measures wind speed and solar radiation, both of which are primary factors affecting the accuracy of the air temperature measurement, correction is possible.   Uncorrected measurements showed errors ranging to 3 °C when compared to measurements made in a state-of-the-art aspirated radiation shield.  After correction, error decreased to < 0.5 °C, and yielded better accuracy than commonly used passive ventilation radiation shields.