Active Standard ASTM F2964 | Developed by Subcommittee: F01.18
Book of Standards Volume: 10.04
Significance and Use
4.5 This test method is described for application to the illumination layer in which case the results apply to that layer only. However, it may be desirable and practical to apply the test to a further assembly or to a fully assembled device with built in illumination. In such a case, the results refer specifically to the subassembly or the entire device respectively.
1.1 This test method covers procedures for determining the uniformity of the luminance of an electroluminescent (EL) lamp. While written specifically for the purpose of evaluating EL devices, which are intrinsically very uniform, it can be applied (judiciously) to the measurement of any diffuse, essentially planar, light source. For specific purposes, it can be applied to partially assembled devices into which the illumination is installed (such as a membrane switch) as a diagnostic for the performance of the entire device. In such a case it must be understood that the results pertain only to the partial assembly and will be modified as the further assembly proceeds.
1.2 The method is to take a 2-dimensional set of measurements, sampling the surface of the unit under test with appropriate density. The method is restricted to measuring luminance only, since variations in color will also show as luminance non-uniformity especially in any photoptically calibrated measuring device.
ICS Number Code 17.180.20 (Colours and measurement of light); 29.140.99 (Other standards relating to lamps)