Document ID: chunk:federal_register_of_legislation:F2023C00158:front:0:p8
Version: federal_register_of_legislation:F2023C00158
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Character Range: 20287–23138

for conducting approval tests and of the administrative departments which grant approval and to which forms certifying approval of extension or refusal or withdrawal of approval, issued in other countries, are to be sent.

       12. TRANSITIONAL PROVISIONS

       The Contracting Parties applying this Regulation:

       12.1. Shall continue to recognize approvals issued for the former Classes I, II and III in respect of the fitting of retro-reflecting devices intended as replacement for vehicles in use;

       12.2. May issue approvals for Classes I and II on the basis of original Regulation (document E/ECE/324-E/ECE/TRANS/505/Add.2 of 23 September 1964) provided that the devices are intended as replacements for fitting to vehicles in use and that it would not be technically feasible for the devices in question to satisfy the photometric requirements for Class I A;

       12.3. May prohibit the fitting of retro-reflecting devices which do not meet the requirements of this Regulation;

       12.3.1. on vehicles for which type approval or individual approval was issued on or after 20 March 1984;

       12.3.2. on vehicles first brought into use on or after 20 March 1985.

       Annex 1

       RETRO-REFLECTING DEVICE

       Symbols and units

         A  = Area of the illumination surface pf the retro-reflecting device
         (cm2)
    C = Centre of reference
    NC = Axis of reference
    Rr = Receiver, observer or measuring device
    Cr = Centre of receiver
    Ør = Diameter of receiver Rr if circular (cm)
    Se = Source of illumination
    Cs = Centre of source of illumination
    Øs = Diameter of source of illumination (cm)
    De = Distance from centre Cs to centre C (m)
    D'e = Distance from centre Cr to centre C (m)

         Note: IN GENERAL, De and D'e are very nearly the same and under normal conditions of observation it may be assumed that De=D'e
         D = Observation distance from and from beyond which the illuminating surface appears to be continuous
    α = Angle of divergence
         β = Illumination angle. With respect to the line CsC which is always considered to be horizonal, this angle is prefixed by the signs - (left), + (right) or - (down), according to the position of the source Se in relation to the axis NC, as seen when looking towards the retro-reflecting device. For any direction defined by two angles, vertical and horizontal, the vertical angle is always given first.
         γ = Angular diameter of the measuring device Rr as seen from point C
    δ = Angular diameter of the source Se as seen from point C
         ε = Angle of rotation. This angle is positive when the rotation is clockwise as seen when looking towards the illuminating surface. If the retro-reflecting is marked "TOP", the position thus indicated is taken as the origin.
    E = Illumination of