用作边缘密封的材料的特性。当模块采用不透水（或极低渗透性）的前片和后片构造，以保护对水分敏感的光伏（PV）材料时，仍然有可能从侧面进入水分。通过在不透水的前片和后片之间的模块周围使用低扩散率材料，可以限制水分进入路径。或者，可能需要使用低扩散率密封剂，这可能会显著降低 在模块的使用寿命内减少水分进入，并以类似于边缘密封材料的方式对其进行评估。购买本文件时可获得的所有当前修订均包含在购买本文件中。

properties of materials designed to be used as edge seals. When modules are constructed with impermeable (or extremely low permeability) front- and backsheets designed to protect moisture-sensitive photovoltaic (PV) materials, there is still the possibility for moisture to get in from the sides. This moisture ingress pathway can be restricted by using a low-diffusivity material around the perimeter of a module between the impermeable front- and backsheets. Alternatively, it can be desirable to use a low-diffusivity encapsulant, which may significantly reduce moisture ingress over the lifetime of the module, and to evaluate it in a similar way to an edge seal material.All current amendments available at time of purchase are included with the purchase of this document.