ASTM F428-19

4.1 Scratches exist on all glass surfaces. Often there are very fine scratches from cleaning operations that are not visible when looking through the glass. Visible scratches may be distracting to the observer looking through the transparency. Therefore, a procedure to define the severity of scratches is useful. A visual standard is used because it is not practical to measure the dimensions of the fine scratches in the scope of this test method.

1.1 This test method covers the visual inspection of scratches on the glass surface of aerospace transparent enclosures.

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 may involve hazardous materials, operations, and equipment. 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.