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Solar glass – Optical properties

The efficiency of solar glass is evaluated using the following parameters:

  • Optical transmission
    Transmission measurement for wave-lengths in the range 0,29 µm to 2,5 µm. For pv applications the transmission measurement can be corrected for the reflection at the glass rear surface.
  • Weighted transmission
    Calculation based on the optical transmission measurement and different weighting spectra result in specific rating numbers; for example the solar transmission from a weighted integration with the AM1.5 solar Spectrum (ISO 9845-1).
  • Incident angle modifier
    Determination of transmission in relation to the angle of incidence. Specific measurement equipment is used for solar thermal or pv applications.

Abbildung SPF Glas Transmission
Abbildung SPF IAM

The required sample size varies according to the desired measurement.