The ICU-3J35 SPECTROHELIOMETER measures the effective irradiance in the spectral zones corresponding to the top, middle, and bottom subcells of a lattice-matched GaInP / GaInAs / Ge triple-junction solar cell.

The ICU-3J35 can be used to monitor the spectral content of solar radiation in a way that is meaningful for predicting performance of such cells, or of concentrator systems that use them and has been developed by the Instituto de Energía Solar (IES-UPM) in Madrid.

Spectro-Heliometer ICU-3J35

Spectro-Heliometer ICU-3J35

Spectro-Heliometer Datasheet Graph



The sensor has been calibrated under real sun conditions by comparison with a reference sensor under clear sky conditions simultaneously to the reference sensor.

Calibration is traceable to balloon flight standards.



With a field of view limited to 5.7º, TRI-BAND SPECTROHELIOMETER measures only the direct beam solar irradiance, thanks to the collimation tube and the specific apertures. It therefore must be mounted on a Solar Tracker and pointed at the sun at all time. The TRI-BAND SPECTROHELIOMETER is designed to be easily installed in any tracker configuration, either mounted flat to a plane perpendicular to the solar vector, or mounted atop an existing normal insolation pyroheliometer.



  • Measure of spectral radiation effects from the sun or light sources.
  • Prediction of current mismatch between subcells of a lattice-matched GaInP / GaInAs / Ge triple-junction solar cell