Document ID: chunk:federal_register_of_legislation:F2023C00228:reg:1:p31
Version: federal_register_of_legislation:F2023C00228
Segment Type: reg
Provision Reference: reg 1 (pt 31/35)
Character Range: 526347–529120

+ 2°C;

       1 hour at 23°C + 5°C and 60-75 per cent RH;

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

               Note: The periods of one hour at 23°C + 5°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 (étalon) lamp, at the following points:

       B 50 L and 50 R for the passing beam of a passing lamp or a passing/driving lamp (B 50 R and 50 L 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 per cent 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 5,500 K and 6,000 K.  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 295 nm and greater than 2,500 nm.  The samples shall be exposed to an energetic illumination of 1,200 W/m2 + 200 W/m2 for a period such that the luminous energy that they receive is equal to 4,500 MJ/m2 + 200 MJ/m2.  Within the enclosure, the temperature measured on the black panel placed on a level with the samples shall be 50°C + 5°C.  In order to ensure a regular exposure, the samples shall revolve around the source of radiation at a speed between 1 and 5 1/min.

       The samples shall be sprayed with distilled water of conductivity lower than 1 mS/m at a temperature of 23°C + 5°C, in accordance with the following cycle:

       spraying:  5 minutes; drying:  25 minutes.

       2.2.2.  Resistance to chemical agents

       After the test described in paragraph 2.2.1. above and the measurement described in paragraph 2.2.3.1. below have been carried out, the outer face of the said three samples shall be treated as described in paragraph 2.2.2.2. with the mixture defined in paragraph 2.2.2.1. below.

       2.2.2.1. Test mixture

       The test mixture shall be composed of 61.5 per cent n-heptane, 12.5 per cent toluene, 7.5 per cent ethyl tetrachloride, 12.5 per cent trichloroethylene and 6