| 2.8. | "Angular diameter of the retro-reflecting device" means the angle subtended by the greatest dimension of the visible area of the illuminating surface, either at the centre of the source of illumination or at the centre of the receiver. | a0c0 |
| 2.8. | "Angular diameter of the retro-reflecting device" means the angle subtended by the greatest dimension of the visible area of the illuminating surface, either at the centre of the source of illumination or at the centre of the receiver. | a0c0 |