The RA01 is a 2-component radiation sensor. It measures the 2 components of the surface radiation balance. By using a thermopile sensor, the work of the device is passive. It generates 4 output voltage proportional to the solar SW and LW flux. The solar radiation sensor and LW sensor is called pyrgeometer. A Pt100 temperature sensor is in the pyrgeometer in order to calculate the sky and the surface temperature.
The device can be heated to avoid deposition of dew and it consists of a 2-axis leveling assembly.