Document ID: chunk:federal_register_of_legislation:F2023C00228:front:0:p90
Version: federal_register_of_legislation:F2023C00228
Segment Type: other
Provision Reference: 
Character Range: 242988–245726

shall be subjected to five cycles of temperature and humidity (RH = relative humidity) change in accordance with the following programme:

       3 hours at 40 degrees C +/- 2 degrees C and 85-95% RH;

       1 hour at 23 degrees C +/- 5 degrees C and 60-75% RH;

       15 hours at -30 degrees C +/- 2 degrees C;

       1 hour at 23 degrees C +/- 5 degrees C and 60-75% RH;

       3 hours at 80 degrees C +/- 2 degrees C;

       1 hour at 23 degrees C +/- 5 degrees C and 60-75% RH;

       Before this test, the samples shall be kept at 23 degrees C +/- 5 degrees C and 60-75% RH for at least four hours.

       Note:

       The period of one hour at 23 degrees C +/- 5 degrees C shall include the periods of transition from one temperature to another which are needed in order to avoid thermal shock effects.

       2.1.2. Photometric measurements

       2.1.2.1. Method

       Photometric measurements shall be carried out on the samples before and after the test. These measurements shall be made using a standard lamp, at the following points:

       B 50L and 50R for the passing beam of a passing lamp or a passing/driving lamp (B 50R and 50L in the case of headlamps intended for left-hand traffic);

       Emax route for the driving beam of a driving lamp or a passing/driving lamp;

       2.1.2.2. Results

       The variation between the photometric values measured on each sample before and after the test shall not exceed 10% including the tolerances of the photometric procedure.

       2.2. Resistance to atmospheric and chemical agents

       2.2.1. Resistance to atmospheric agents

       Three new samples (lenses or samples of material) shall be exposed to radiation from a source having a spectral energy distribution similar to that of a black body at a temperature between 5,500K and 6,000K. Appropriate filters shall be placed between    the source and the samples so as to reduce as far as possible radiations with wave lengths smaller than 295nm and greater than 2,500nm. The samples shall be exposed to an energetic illumination of 1,200W/m2 +/- 200W/m2 for a period such that the luminous energy that they receive is equal to 4,500MJ/m2 +/- 200MJ/m2.  Within the enclosure, the temperature measured on the black panel placed on a level with the samples shall be 50 degrees C +/- 5 degrees C. In order to ensure a regular exposure, the samples shall revolve around the source of radiation at a speed between 1 and 51/min.

       The samples shall be sprayed with distilled water of conductivity lower than

       1 mS/m at a temperature of 23 degrees C +/- 5 degrees C, in accordance with the following cycle:

       spraying:  5 minutes;

       drying:  25 minutes.

       2.2.2. Resistance