Document ID: chunk:federal_register_of_legislation:F2023C00228:reg:1:p13
Version: federal_register_of_legislation:F2023C00228
Segment Type: reg
Provision Reference: reg 1 (pt 13/15)
Character Range: 569188–572018

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 device is strong enough to withstand 50,000 operations without suffering damage despite the vibrations to which it may be subjected in normal use;

       5.8.2. in the case of  failure it shall automatically obtain the passing beam position;

       5.8.3. either the passing beam or the driving beam shall always be obtained without any possibility of the mechanism stopping in between the two positions;

       5.8.4. the user cannot, with ordinary tools, change the shape or position of the moving parts.

       6. ILLUMINATION

       6.1. General provisions

       6.1.1. Headlamps shall be so made that they give adequate illumination without dazzle when emitting the passing beam, and good illumination when emitting a driving beam.

       6.1.2. The illumination produced by the headlamp shall be determined by means of a vertical screen set up 25 m forward of the headlamp and at right angles to its axes as shown in Annex 3 to this Regulation.

       6.1.3. Headlamps shall be checked by means of an uncoloured standard (étalon) filament lamp designed for a rated voltage as indicated in the relevant data sheet of Regulation No. 37.  During the checking of the headlamp, the voltage at the terminals of the filament lamp shall be regulated so as to obtain the reference luminous flux as indicated at the relevant data sheet of Regulation No. 37.

       6.1.4. The headlamp shall be considered acceptable if it meets the requirements of this paragraph 6 with at least one standard (étalon) filament lamp, which may be submitted with the headlamp.

       6.2. Provisions concerning passing beams

       6.2.1. For a correct aiming the passing beam shall produce a sufficiently sharp "cut-off" to permit a satisfactory visual adjustment with its aid as indicated in paragraph 6. below.  The "cut-off" must be substantially horizontal and shall be as straight as possible from at least 3° L to 3° R for Class A, B, C and D headlamps.  In case that visual aim leads to problems or ambiguous positions, the instrumental method as specified in Annex 9, paragraphs 2. and 4., shall be applied and the quality or rather the sharpness of the "cut-off" and the linearity shall be checked on performance.
6.2.2. The headlamp shall be so aimed that:

       6.2.2.1. For horizontal adjustment:  The beam is as symmetrical as possible with reference to line V-V;

       6.2.2.2. For vertical adjustment:  The horizontal part of the "cut-off" line is adjusted to its nominal position 1 per cent below the H-H-line which is 10 cm below the headlamp axis on the