Document ID: chunk:federal_register_of_legislation:F2015C00542:reg:254:p10
Version: federal_register_of_legislation:F2015C00542
Segment Type: reg
Provision Reference: reg 254 (pt 10/18)
Character Range: 125347–128321

between them.

               Precautions shall be taken to prevent condensate from the walls or ceiling of the test chamber from falling on the test pieces.

              7.2. Indices of difficulty of the secondary characteristics

                Colourless Tinted

               Colouring of interlayer 1 2

               The other secondary characteristics are not involved.

              7.3. Interpretation of results

              7.3.1. Safety glazing shall be deemed to be satisfactory from the point of view of resistance to humidity if no significant change is observed more than 10 mm from the uncut edges and more than 15 mm from the cut edges after ordinary and treated laminated glass glazing have been maintained for two hours in the ambient atmosphere, and plastics-faced and glass-plastics glazing have been maintained for 48 hours in the ambient atmosphere.

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

              8. Test of resistance to temperature changes

              8.1. Test method

               Two test pieces 300 mm x 300 mm shall be placed in an enclosure at a temperature of -40 °C ± 5 °C for a period of 6 hours; they shall then be placed in the open air at a temperature of 23 °C ± 2 °C for one hour or until temperature equilibrium has been reached by the test pieces. These shall then be placed in circulating air at a temperature of 72 °C ± 2 °C for 3 hours. After being placed again in the open air at 23 °C ± 2 °C and cooled to that temperature, the test pieces shall be examined.

              8.2. Indices of difficulty of secondary characteristics

                             Colourless  Tinted

Colouring of the interlayer  1           2
or of the plastics coating

               The other secondary characteristics are not involved.

              8.3 Interpretation of results

               The test for resistance to temperature changes shall be considered to have given a satisfactory result if the test pieces do not show any evidence of cracking, clouding, separation of layers or other apparent deterioration.

              9. Optical qualities

              9.1. Light transmission test

              9.1.1. Apparatus

              9.1.1.1. Light source consisting of an incandescent lamp with its filament contained within a parallelepiped measuring 1.5 mm x 1.5 mm x 3 mm. The voltage at the lamp filament shall be such that the colour temperature is 2,856 K ± 50 K. This voltage shall be stabilized within ±1/1,000. The instrument used to check the voltage shall be of appropriate accuracy.

              9.1.1.2. Optical system consisting of a lens with a focal length f of at least 500 mm and corrected for chromatic aberrations. The full aperture of the lens shall not exceed f/20. The distance between the lens and