Document ID: chunk:federal_register_of_legislation:F2023C00228:reg:1:p12
Version: federal_register_of_legislation:F2023C00228
Segment Type: reg
Provision Reference: reg 1 (pt 12/15)
Character Range: 566685–569452

paragraphs 6. to 8. below.

       5.2. Headlamps shall be so made as to retain their prescribed photometric characteristics and to remain in good working order when in normal use, in spite of the vibrations to which they may be subjected.

       5.2.1. Headlamps shall be fitted with a device enabling them to be so adjusted on the vehicles as to comply with the rules applicable to them.  Such a device may or may not provide horizontal adjustment, provided that the headlamps are so designed that they can maintain a proper horizontal aiming even after the vertical aiming adjustment.  Such a device need not be fitted on units in which the reflector and the diffusing lens cannot be separated, provided the use of such units is confined to vehicles on which the headlamp setting can be adjusted by other means.

       Where a headlamp providing a passing beam and a headlamp providing a driving beam, each equipped with its own filament lamp, are assembled to form a composite unit the adjusting device shall enable each optical system individually to be duly adjusted.

       5.2.2. However, these provisions shall not apply to headlamp assemblies whose reflectors are indivisible. For this type of assembly the requirements of paragraph 6.3. of this Regulation apply.

       5.3. The headlamp shall be equipped with filament lamp(s) approved according to Regulation No. 37.  Any Regulation No. 37 filament lamp may be used, provided that:

           (a) no restriction on the application is made in the table of contents of that Regulation;

           (b) for Class A and B, its reference luminous flux for dipped‑beam does not exceed 600 lm;

           (c) for Class C and D, its objective luminous flux for dipped-beam does not exceed 2000 lm.

       5.4. The components by which a filament lamp is fixed to the reflector shall be so made that, even in darkness, the filament lamp can be fixed in no position but the correct one. [33]/

       5.5. The filament lamp holder shall conform to the characteristics given in IEC Publication 61-2, third edition, 1969.  The holder data sheet relevant to the category of filament lamp used, applies.

       5.6. In addition, Class B or C or D headlamps shall be complementary tested according to the requirements of Annex 4 to ensure that in use there is no excessive change in photometric performance.

       5.7. If the lens of a Class B or C or D headlamp is of plastic material, tests shall be done according to the requirements of Annex 6.

       5.8. On headlamps designed to provide alternately a driving beam and a passing beam, any mechanical, electromechanical or other device incorporated in the headlamp for switching from one beam to the other shall be so constructed that:

       5.8.1. the