IEC 62788-1-4:20 16+A1:2020提供了一种用于测量光伏(PV)模块中使用的封装材料的光学透射率的方法。该程序中的标准化测量量化了封装对PV电池的预期透射率。太阳加权透射率的后续计算允许在不同材料之间进行比较。未风化材料的结果可用于封装制造商的数据表、制造商的材料或工艺开发、制造质量控制（材料验收）或应用于模块性能分析。该测量方法还可用于监测封装材料风化后的性能，以帮助评估其耐久性。该合并版本由第一版（2016年）及其修正案1（2020年）组成。因此，除本出版物外，无需下令修订。

IEC 62788-1-4:2016+A1:2020 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. This consolidated version consists of the first edition (2016) and its amendment 1 (2020). Therefore, no need to order amendment in addition to this publication.