Document ID: chunk:federal_register_of_legislation:F2023C00158:front:0:p12
Version: federal_register_of_legislation:F2023C00158
Segment Type: other
Provision Reference: 
Character Range: 31080–34069

retro-reflecting optical units shall not be replaceable unless they consist of approved retro-reflecting devices in Class I A.

       2.6. The outside edges of the illuminating surfaces of triangular retro-reflecting devices in Class III A shall be between 150 and 200mm long.  In the case of devices of hollow- triangle type, the width of the sides, measured at right angles to the latter, shall be equal to at least 20% of the effective length between the extremities of the illuminating surface.

       3. SHAPE AND DIMENSIONS OF RETRO-REFLECTING DEVICES IN CLASS IV A

       3.1. The shape of the light emitting surfaces must be simple and not easily confused at normal observation distances with a letter, a digit or a triangle.  However, a shape resembling the letters and digits of simple form, O, I, U and 8 is permissible.

       3.2. The light emitting surface of the retro-reflecting device must be at least 25cm2.

       4. COMPLIANCE WITH THE ABOVE SPECIFICATIONS SHALL BE VERIFIED BY VERIFIED BY VISUAL INSPECTION.

       Annex 5 - Appendix

       RETRO-REFLECTING FOR TRAILERS - CLASS III A

Note: These sketches are for illustration purposes only.

       Annex 6

       COLORIMETRIC SPECIFICATIONS

       1. These specifications shall apply only to clear, red or amber retro-reflecting devices.

       1.1. Retro-reflecting devices may consist of a combined retro-reflecting optical unit and filter, which must be so designed that they cannot be separated under normal conditions of use.

       1.2. The colouring of retro-reflecting optical units and filters by means of paint or varnish is not permitted.

       2. When the retro-reflecting device is illuminated by ICI standard illuminant A, with an angle of divergence of 1/3 degrees and an illumination angle V=H= 0 degrees, or, if this produces a colourless surface reflection, an angle V= +/- 5 degrees, H = 0 degrees, the trichromatic coordinates of the reflected luminous flux must be within the following limits:

       RED: Limit towards yellow:  y < 0.335

         Limit toward purple:  z < 0.008

       AMBER: Limit towards yellow  y < 0.429

         Limit towards red:  y < 0.398

         Limit towards white:  z > 0.007

       2.1. In the case of red and amber, compliance with the colorimetric specifications shall be verified by a visual comparison test.

       2.2. If any doubt remains after this test, compliance with the colorimetric specifications shall be verified by determining the trichromatic co-ordinates of the most doubtful sample.

       3. Clear retro-reflecting devices must not produce a selective reflection, that is to say, the trichromatic co-ordinates "x" and "y" of the standard illuminant "A" used to illuminate the retro-reflecting device must not undergo a change of more than 0.01 after reflection by the retro-reflecting device.

       3.1. This shall be verified by the visual comparison test indicated above, the control field being illuminated by a light