【国外标准】 Standard Test Method for Determining Luminance of a Membrane Switch Backlit with Diffuse Light Source (Withdrawn 2024)

3.1 Illumination of a switch or of certain features of a switch often has a functional purpose and must meet specification to satisfy the functional requirements of the switch.3.2 Illumination of the switch can be affected by variations in the quality and design of the overlay and its application.3.3 This test method addresses only the optical and visual appearance of the switch and not its electrical function.3.4 This test method is non-destructive.3.5 If this test method is applied to the entire switch assembly, the results can be applied to the whole device. However, it may be sufficient and practical to apply the test either to a subassembly only, or to the illumination layer only, in which case the results apply to that layer only and the net effect on the fully assembled device must be calculated, extrapolated, or otherwise inferred.1.1 This test method covers procedures for determining the luminance of a backlit membrane switch. As written, it applies to a fully assembled switch. For specific purposes, it can be applied to partially assembled switches with the understanding that the results pertain only to the partial assembly and will be modified as the further assembly proceeds.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.