【国外标准】 Standard Practice for Viewing Conditions for Visual Inspection of Membrane Switches (Withdrawn 2023)

3.1 This practice is designed to enable all manufacturers and users of membrane switches to perform visual inspections under uniform conditions. The aim is to eliminate key variables in the inspection procedures so specimens can be viewed more objectively.3.2 Viewing specimens under these conditions could reveal cosmetic defects in the specimen. Many of these defects or flaws are due to variables in the raw materials or the manufacturing process. These cosmetic flaws or defects do not necessarily mean that the specimen is defective. The determination of whether a specimen is acceptable or defective varies with the application and the needs of the user. Therefore, customer and vendor must agree on acceptable quality standards prior to manufacturing.3.3 This practice does not establish standards for acceptability of specimens, only how they must be viewed (inspected).3.4 This practice is not intended to be used for color matching purposes. Color matching must be performed under more precise lighting conditions outside the scope of this practice.1.1 This practice covers procedures for performing visual inspection of membrane switches. This includes visual inspection of overlays and circuitry.1.2 This practice defines lighting parameters, distance from eye to specimen, viewing angle, and the viewing time allowed for a specific size specimen.1.3 This practice is only designed for visual inspection of aesthetic qualities of membrane switches. It is not intended for color matching or gloss measurement.1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.