Document ID: chunk:federal_register_of_legislation:F2023C00154:front:0:p28
Version: federal_register_of_legislation:F2023C00154
Segment Type: other
Provision Reference: 
Character Range: 73803–76485

in Japan (E 43) under number 321.
Figure 14

Annex 4

Measuring screen geometry and measuring grid
    1. Measuring screen
The co-ordinates are specified in degrees for spherical angles in a web with a vertical polar axis (see Figure 1).

Figure 1

     2. Measuring grid (see Figure 2)
      The measuring grid is symmetrical about the v‑v line (see table in paragraph 6.4.3. of this Regulation). For simplicity the angular web is shown in the form of a rectangular grid.
     2.1. In the case of front fog lamps of Class "B", the measuring grid is shown in Figure 2.
     Figure 2

     2.2. In the case of front fog lamps of Class "F3", the measuring grid is shown in Figure 3.
Figure 3

Light distribution of the Class F3 front fog lamp

Annex 5

Tests for stability of photometric performance of front fog lamps in operation (tests on complete front fog lamps)
Once the photometric values have been measured according to the prescriptions of this Regulation, in the point of maximum illumination in zone D (Emax) and in the point HV, a complete front fog lamp sample shall be tested for stability of photometric performance in operation. "Complete front fog lamp" is the complete lamp itself including those surrounding body parts and lamps, which could influence its thermal dissipation.
The tests shall be carried out:

       (a) In a dry and still atmosphere at an ambient temperature of 23 C ± 5 C, the test sample being mounted on a base representing the correct installation on the vehicle;
       (b) In case of replaceable light sources: using mass production filament light sources, which have been aged for at least one hour, or mass production gas‑discharge light sources, which have been aged for at least 15 hours or mass production LED modules which has been aged for at least 48 hours and cooled down to ambient temperature before starting the tests as specified in this Regulation. The LED modules supplied by the applicant shall be used.
The measuring equipment shall be equivalent to that used during headlamp type approval tests.

The test sample shall be operated without being dismounted from or readjusted in relation to its test fixture. The light source used shall be a light source of the category specified for that front fog lamp.

1. Test for stability of photometric performance
1.1. Clean front fog lamp
The front fog lamp shall be operated for 12 hours as described in paragraph 1.1.1. and checked as prescribed in paragraph 1.1.2. below.
1.1.1. Test procedure
 The front fog lamp shall be operated as follows:
1.1.1.1. In the case where only one lighting function (front fog lamp) is to be approved, the corresponding light source is lit