How do solar radiation sensors measure direct solar energy?

The solar radiation sensor measures the direct radiant energy from the sun mainly through the following steps:

Sensing the sun's rays: the solar radiation sensor has a built-in high-precision light-sensitive element, when the sun's rays irradiate the light-sensitive element, the light-sensitive element will be converted into an electrical signal.

Measuring electrical signals: The sensor processes and measures the converted electrical signals. These electrical signals reflect the intensity and spectral distribution of solar radiation.

Data processing and output: The sensor processes the measured data and outputs it in a readable data format. Typically, the sensor transmits the data to a host computer or data acquisition system via a serial port or network.

During the measurement process, the solar radiation sensor senses the sun's rays including not only the radiation directly from the sun, but also the radiation after scattering by the atmosphere.

Therefore, the direct solar radiation energy measured by the sensor is the total radiant energy after scattering through the atmosphere. If a purer measure of direct solar radiation energy is required, it can be measured outside the atmosphere, for example, by installing solar radiation sensors on satellites for observation.

Pyranometer Solar Radiation Sensors data sheet

NBL-W-HPRS-Solar-Radiation-Sensor-Instruction-Manual-V3.0.pdf

NBL-W-SRS-Solar-radiation-sensor-instruction-manual-V4.0.pdf