Document ID: chunk:federal_register_of_legislation:F2023C00142:reg:21:p1
Version: federal_register_of_legislation:F2023C00142
Segment Type: reg
Provision Reference: reg 21 (pt 1/15)
Character Range: 34389–37510

21                                                                           0.2 min                   L 175                      0
A to B                                                Segment I              6 min                     L 225 to R225              D 37.5
C to D                                                Segment II             6 max                     R 140 to R 396             U 45
E to F                                                Segment III and under  20 max                    L 417 to R 375             D 187.5
                                                      E max R                70 max                    Right of VV line           Above D 75
                                                      E max L                50 max                    Left of VV line

       6.3. Provisions concerning driving beams

       6.3.1. In the case of a headlamp designed to provide a driving beam and a passing beam, measurements of the illumination produced on the screen by the driving beam shall be taken with the same headlamp alignment as for measurements under paragraph 6.2.6. above; in the case of a headlamp providing a driving beam only, it shall be so adjusted that the area of maximum illumination is centred on the point of intersection of lines HH and VV; such a headlamp needs meet only the requirements referred to in paragraph 6.3. Test voltages are the same as in paragraph 6.2.5.1.

       6.3.2. It is possible to use several light sources for the driving beam, these light sources being listed in either Regulation No. 37 or Regulation No. 99.  The following provisions shall be met:

       6.3.2.1. The point of intersection (HV) of the lines HH and VV shall be situated within the isolux representing 80 % of the maximum illuminance.  This maximum illuminance, hereunder designated as Emax, shall lie between 70 and 180 lux.

       6.3.2.2. The reference mark referred to in paragraph 4.2.2.7. above shall be obtained by means of the formula:

       Reference mark = 0,208 Emax

       This value shall be rounded off to the value: 17.5 - 20 - 25 - 27.5 - 30 - 37.5.

       6.3.2.3. Starting from point HV, horizontally to the right and left, the illuminance shall be not less than 40 lux up to a distance of 1.125m and not less than 10 lux up to a distance of 2.25 m.

       6.4. The screen illuminance values mentioned in paragraphs 6.2.6. to 6.3.2.3. above shall be measured by means of a photo-receptor, the effective area of which shall be contained within a square of 65 mm side.

       6.5. Provisions concerning movable reflectors

       6.5.1. With the lamp fixed according to all the positions described in paragraph 2.1.4., the headlamp must meet the photometric requirements of paragraph 6.2. or 6.3., or both.

       6.5.2. Additional tests are made after the reflector has been tilted vertically upwards by the angle quoted in paragraph 2.1.4. or 2 degrees, whichever is smaller, by means of the headlamp aiming devices.  The headlamp is then re-aimed downwards (by means of the goniometer), and the photometric specifications must be met at the