Document ID: chunk:federal_register_of_legislation:F2023C00134:body:0:p9
Version: federal_register_of_legislation:F2023C00134
Segment Type: other
Provision Reference: 
Character Range: 22164–24860

masking.

       1.2. In the event that the results of measurements are challenged, measurements shall be taken in such a way as to meet the following requirements:

       1.2.1. the distance of measurement shall be such that the law of the inverse of the square of the distance is applicable;

       1.2.2. the measuring equipment shall be such that the angle subtended by the receiver from the reference centre of the light is between 10' and 1 degrees;

       1.2.3. the intensity requirement for a particular direction of observation shall be satisfied if the required intensity is obtained in a direction deviating by not more than one quarter of a degree from the direction of observation.

       2. Measuring points expressed in degrees of angle with the axis of reference and values of the minimum intensities of the light emitted

2.1. The directions H = 0 degrees and V = 0 degrees correspond to the axis of reference. On the vehicle they are horizontal, parallel to the median longitudinal plane of the vehicle and oriented in the required direction of visibility. They pass through the centre of reference. The values shown in the table give, for the various directions of measurement, the minimum intensities in cd.
2.2. If visual examination of a lamp appears to reveal substantial local variations of intensity, a check shall be made to ensure that no intensity measured between two of the directions of measurement referred to above is below 50% of the lower minimum intensity of the two prescribed for these directions of measurement.
3. Photometric measurement of lamps equipped with several light sources
The photometric performance shall be checked:
3.1. For non-replaceable light sources (filament lamps and other):
with the light sources present in the lamp, in accordance with paragraph 7.1.1. of this Regulation.
3.2. For replaceable filament lamps:
when equipped with mass production filament lamps at 6.75 V, 13.5 V or 28.0 V the luminous intensity values produced shall lie between the maximum limit given in this Regulation and the minimum limit of this Regulation increased according to the permissible deviation of the luminous flux permitted for the type of filament lamp chosen, as stated in Regulation No. 37 for production filament lamps; alternatively a standard filament lamp may be used in turn, in each of the individual positions, operated at its reference flux, the individual measurements in each position being added together.
Annex 4
COLOUR OF WHITE LIGHT
(Trichromatic coordinates)

Limit towards blue : x > 0.310
" " yellow : x < 0.500
" " green : y < 0.150 + 0.640x
" " green : y < 0.440
" " purple : y > 0.050 + 0.750x
" " red : y > 0.382
For