Luminance factor Clause Samples
The luminance factor clause defines the required level of brightness or light reflectance for a material, surface, or product. In practice, this clause specifies measurable standards—such as minimum or maximum luminance values—that must be met, often referencing industry benchmarks or testing methods. Its core function is to ensure that materials provide adequate visibility, safety, or aesthetic consistency, thereby addressing issues related to lighting quality and compliance with regulatory or design requirements.
Luminance factor. The luminance factor β shall be at least as indicated in table 3.
1. Resistance to weathering
1.1. Procedure - For each test, two specimens of a sample unit (see paragraph 2.1.2. of this Regulation) are taken. One specimen shall be stored in a dark and dry container for subsequent use as "reference unexposed specimen. The second specimen shall be subjected to a source of illumination in accordance with ISO Standard 105 - B02 - 1978, Section 4.3.1; the retro-reflective material shall be exposed until blue standard No. 7 has faded to No. 4 on the grey scale and the fluorescent material until blue standard No. 5 has faded to No. 4 on the grey scale. After the test, the specimen shall be washed in a dilute neutral detergent solution, dried and examined for conformity with the requirements specified in paragraphs 1.2. to 1.4.
1.2. Visual appearance - No area of the exposed specimen shall show any evidence of cracking, scaling, pitting, blistering, delamination, distortion, chalking, staining or corrosion. There shall be no shrinkage in excess of 0.5 per cent in any linear direction and no evidence of adhesion failure such as edge lifting from the substrate.
1.3. Colour fastness - The colours of the exposed specimens shall still meet the requirements in Annex 6, tables 1, 2 and 3.
Luminance factor the ratio of luminance of a surface to that of a perfect reflector, identically illuminated.