A.5 Measurements
A.5.1 The surface luminance measurements shall be conducted using a fixed geometry instrument calibrated in accordance with appropriate national standards.
A.5.2 The arrangement of the measurement instrument shall ensure that the results are not affected by extraneous light.
A.5.3 The test patch to be measured on each sample shall be consistent between tests and have a diameter of between 25 mm and 50 mm.
A.5.4 The tests shall assess the full luminance decay required in clause 4.2.2 of this Standard.
A.5.5 The measuring instrument shall incorporate a fast response photometer head with CIE* photopic correction and have a measurement range of at least 10-4cd/m2 to 10cd/m2.
NOTE it the results are within 10% of the required luminance the measurements should be confirmed with an instrument having a measurement range of 10-5cd/m2 to 10cd/m2.
A.6 Results
Results should be presented in any format that clearly establishes the excitation illuminance that will allow the products to provide the minimum required luminance after 10 minutes and after 60 minutes.
*International Commission on Illumination.
