| 5.9.4.2.1. | The CIL measured on random slices of 50 mm length of the retro-reflective device shall lie between extremes having a ratio not in excess of 3. These slices are taken between the perpendiculars to the side of the triangle and passing through the corresponding apexes of the central aperture. This requirement applies to an angle of divergence of 20' and to illumination angles of V = 0°, H = 0° or ± 5° and V = ± 20°, | a0c0 |