可见光穿透率 Visible Light Transmitted

The ratio of visible light transmitted through the window to that which is incident upon the window.    太阳光穿过玻璃窗的可见光的数量与投射在上面的之比。    或：在可见光谱（380纳米至780纳米）范围内，透过玻璃的光强度对入射光强度的百分比。