ASTM F2156-01
Historical Standard: ASTM F2156-01 Standard Test Method for Measuring Optical Distortion in Transparent Parts Using Grid Line Slope
SUPERSEDED (see Active link, below)
ASTM F2156
1. Scope
1.1 When an observer looks through an aerospace transparency, relative optical distortion results, specifically in thick, highly angled, multilayered plastic parts. Distortion occurs in all transparencies but is especially critical to aerospace applications such as combat and commercial aircraft windscreens, canopies, or cabin windows. This is especially true during operations such as takeoff, landing, and aerial refueling. It is critical to be able to quantify optical distortion for procurement activities.
1.2 This test method covers apparatus and procedures that are suitable for measuring the grid line slope (GLS) of transparent parts, including those that are small or large, thin or thick, flat or curved, or already installed. This test method is not recommended for raw material.
1.3 The values stated in SI units shall be regarded as the standard. The values given in parentheses are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
ASTM Standards
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
F733 Practice for Optical Distortion and Deviation of Transparent Parts Using the Double-Exposure Method
F801 Test Method for Measuring Optical Angular Deviation of Transparent Parts
Keywords
canopy; distortion; grid board; grid line slope; transparency; window; windscreen; Aerospace transparent enclosures; Canopies (aerospace applications); Distortion; Grid-line slope; Windows/window assemblies; Windscreens
ICS Code
ICS Number Code 49.020 (Aircraft and space vehicles in general)
DOI: 10.1520/F2156-01
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