Document ID: chunk:federal_register_of_legislation:F2023C00228:front:0:p44
Version: federal_register_of_legislation:F2023C00228
Segment Type: other
Provision Reference: 
Character Range: 118751–121374

only  50 + 0%                                50 + 0%

       8. ILLUMINATION [6/]

       8.1. SB units shall be so made as to give adequate illumination without dazzle for the passing beam, and good illumination for the driving beam.

       8.2. The illumination produced by the unit shall be checked on a vertical screen set at a distance of 25 m in front of the unit and .at right angles to its axis (see annex 4, plates SB8a and SB8b).

       8.3. The passing beam must produce a sufficiently sharp "cut-off" to permit satisfactory alignment with its aid.  The "cut-off" must be a horizontal line on the side opposite to the direction of the traffic for which the unit is intended; on the other side it should be horizontal or within an angle of 15 degrees above the horizontal.

       8.4. The SB unit shall be aimed so that on passing beam:

       8.4.1. In the case of units designed to meet the requirements of right-hand traffic, the "cut-off" on the left half of the screen [7/] is horizontal and, in the case of units designed to meet the requirements of  left-hand  traffic, the "cut-off" on the right  half of the screen is horizontal;

       8.4.2. This horizontal part of the "cut-off" is situated, on the screen, 25 cm below the level of the horizontal plane passing through the focus of the unit (see annex 4, plates SB8a and SB8b);

       8.4.3. The screen is in the position indicated in annex 4, plates SB8a and SB8b.[8/]

       8.5. When so aimed, the unit need, if its approval is sought solely for a passing beam,[9/] meet only the requirements referred to in paragraph 8.8 below; if it is intended to provide both a passing beam and a driving beam it shall meet the requirements referred to in paragraphs 8.8 and 8.9.

       8.6. Where an SB unit so aimed does not meet the requirements referred to in paragraphs 8.8 and 8.9 below, its alignment may be changed, provided that the axis of the beam is not laterally displaced by more than 1 degrees (= 44 cm) to the right or left. 10/  To facilitate alignment by means of the "cut-off", the unit may be partially occulted in order to sharpen the "cut-off".

       8.7. In the case of an SB unit providing a driving beam only, it shall be so aimed that the area of maximum illumination is centred on the point of intersection HV of the lines hh and vv; such a unit need meet only the requirements referred to in paragraph 8.9.

       8.8. The illumination produced on the screen by the passing beam shall meet the following requirements:

       Table 2

Point on measuring screen        Required illumination in lux
SB units for right-hand