Radiation received by direct solar rays. Measured by a pyrheliometerAn instrument used for measuring direct beam solar irradiance. Uses... with a solar aperture of 5.7° to transcribe the solar disc.
Radiation received by direct solar rays. Measured by a pyrheliometerAn instrument used for measuring direct beam solar irradiance. Uses... with a solar aperture of 5.7° to transcribe the solar disc.