Document ID: chunk:federal_register_of_legislation:F2023C00153:front:0:p14
Version: federal_register_of_legislation:F2023C00153
Segment Type: other
Provision Reference: 
Character Range: 39044–41895

and then left to dry. This procedure shall be repeated until the illumination value has dropped to 15-20 % of the values measured for each following point under the conditions described in this annex:
Point of Emax in driving beam, photometric distribution for a driving/passing lamp, Point of Emax in driving beam, photometric distribution for a driving lamp only,
B 50 and 50 V [5/] for a passing lamp only.
1.2.1.3.                        Measuring equipment
The measuring equipment shall be equivalent to that used during headlamp approval tests. A standard (reference) filament lamp shall be used for the photometric verification.
2.                                          TEST FOR CHANGE IN VERTICAL POSITION OF THE CUT-OFF LINE UNDER THE INFLUENCE OF HEAT
This test consists of verifying that the vertical drift of the cut-off line under the influence of heat does not exceed a specified value for an operating passing lamp.
The headlamp tested in accordance with paragraph 1., shall be subjected to the test described in 2.1., without being removed from or readjusted in relation to its test fixture.
2.1.                                    Test
The test shall be carried out in a dry and still atmosphere at an ambient temperature of 23 degrees C +/-5 degrees C.
Using a mass production filament lamp which has been aged for at least one hour the headlamp shall be operated on passing beam without being dismounted from or readjusted in relation to its test fixture. (For the purpose of this test, the voltage shall be adjusted as specified in paragraph 1.1.1.2). The position of the cut-off line in its horizontal part (between the vertical lines passing through point 50 L and 50R) shall be verified 3 minutes (r3) and 60 minutes (r60) respectively after operation.
The measurement of the variation in the cut-off line position as described above shall be carried out by any method giving acceptable accuracy and reproducible results.
2.2.                                    Test results
2.2.1.                              The result in milliradians (mrad) shall be considered as acceptable for a passing lamp, only when the absolute value deltarI = (r3 - r60) recorded on the headlamp is not more than 1.0 mrad (deltarI < 1.0 mrad).
2.2.2.                              However, if this value is more than 1.0 mrad but not more than 1.5 mrad
(1.0 mrad < deltarI < 1.5 mrad) a second headlamp shall be tested as described in 2.1 after being subjected three consecutive times to the cycle as described below, in order to stabilize the position of mechanical parts of the headlamp on a base representative of the correct installation on the vehicle:
Operation of the passing lamp for one hour (the voltage shall be adjusted as specified in paragraph 1.1.1.2),
Period of rest for one hour.
The headlamp type shall be considered as acceptable