Lighting by means of luminaires with a light distribution such that not more than 10 per cent of the emitted luminous flux reaches the working plane direct, assuming that this plane is unbounded.

• 采用具有一定配光曲线的灯具进行照明，在不考虑工作面边界时使得直接到达工作面的光通不超过总光通的10%25的照明方式。