【国外标准】 Standard Practice for Optical Distortion and Deviation of Transparent Parts Using the Double-Exposure Method

5.1 Transparent parts, such as aircraft windshields and windows, can be inspected using this practice, and the amount of optical distortion or deviation can be measured. The measurement shall be checked for acceptability against the specification for the part. The photograph (digital file, print, or negative) shall be maintained as a permanent record of the optical quality of the part.1.1 This photographic practice determines the optical distortion and deviation of a line of sight through a simple transparent part, such as a commercial aircraft windshield or a cabin window. This practice applies to essentially flat or nearly flat parts moreso than to highly curved materials.1.2 Test Method F801 addresses optical deviation (angular deviation), and Test Method F2156 addresses optical distortion using grid line slope. Use these test methods instead of Practice F733 whenever practical.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 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.