IEC 62788-1-4 Ed. 1.1 b PDF

IEC 62788-1-4 Ed. 1.1 b – Measurement procedures for materials used in photovoltaic modules – Part 1-4: Encapsulants – Measurement of optical transmittance and calculation of the solar-weighted photon transmittance, yellowness index, and UV cut-off wavelength CONSOLIDATED EDITION

IEC 62788-1-4:2020 provides a method for measurement of the optical transmittance of encapsulation materials used in photovoltaic (PV) modules. The standardized measurements in this procedure quantify the expected transmittance of the encapsulation to the PV cell. Subsequent calculation of solar-weighted transmittance allows for comparison between different materials. The results for unweathered material may be used in an encapsulation manufacturer’s datasheets, in manufacturer’s material or process development, in manufacturing quality control (material acceptance), or applied in the analysis of module performance. This measurement method can also be used to monitor the performance of encapsulation materials after weathering, to help assess their durability.