Document ID: chunk:federal_register_of_legislation:F2015C00542:reg:254:p7
Version: federal_register_of_legislation:F2015C00542
Segment Type: reg
Provision Reference: reg 254 (pt 7/18)
Character Range: 116795–120064

6.1.4. Each test piece or sample (total number 3 pieces) shall be subjected, in accordance with the procedure above, to radiation such that the radiation on each point of the test piece or sample produces on the interlayer used the same effect as that which would be produced by solar radiation of 1,400 W/m2 for 100 hours.

              6.2. Indices of difficulty of the secondary characteristics

                Colourless Tinted

               Colouring of glass 2 1

               Colouring of interlayer 1 2

               The other secondary characteristics are not involved.

              6.3. Interpretation of results

              6.3.1. The test for resistance to radiation shall be deemed to have given a positive result if the following conditions are fulfilled:

              6.3.1.1. The total light transmittance when measured pursuant to paragraphs 9.1.1. and 9.1.2. of this annex does not fall below 95 per cent of the original value before irradiation and in any event does not fall:

              6.3.1.1.1. Below 70 per cent in the case of windscreens and other glazing located in a position requisite for driving visibility.

              6.3.2. A set of test pieces or samples submitted for approval shall be considered satisfactory from the point of view of the resistance to radiation test if all the tests have given a satisfactory result.

              6.4. Resistance to simulated weathering

              6.4.1. Test method

              6.4.1.1. Apparatus

              6.4.1.1.1. Long arc xenon lamp

               The exposure apparatus[12] shall utilize a long arc xenon lamp as the source of irradiation, but other methods giving the required level of ultraviolet radiant exposure shall be allowed. The long arc xenon lamp is advantageous in that it can, when correctly filtered and maintained, yield a spectrum most closely approximating that of natural sunlight. To this end, the quartz xenon burner tube shall be fitted with suitable borosilicate glass optical filter(s)[13]. The xenon lamps employed shall be operated, from a suitable 50 or 60 Hz power supply suitable reactance transformers and electrical equipment.

               The exposure apparatus shall include equipment necessary for measuring and/or controlling the following:

                  (a) Irradiance

                  (b) Black standard temperature

                  (c) Water spray

                  (d) Operating schedule or cycle

               The exposure apparatus shall be made from inert materials which do not contaminate the water employed in the test.

               Irradiance shall be measured at the surface of the test piece surface and shall be controlled according to the recommendations of the exposure apparatus manufacturer.

               Total ultraviolet[14] radiant exposure (Joules per square metre) shall be measured or computed and shall be considered the primary measure of test piece exposure.

              6.4.1.2. Test pieces

               The dimensions of the test pieces shall norma11y be those specified in the appropriate test method for the property or properties to be measured after exposure.

               The number of control and test pieces for each test condition or exposure stage shall