ASTM E 242 : 2015 : R2020

1.1This document describes the appearance of a radiographic image where fundamental components of image quality are changed, that is, variables such as whether an X-ray or gamma ray source was used, the characteristics of the radiographic film (gradient, granularity, and developing conditions) and intensifying screens, and specimen thickness (the geometrical configuration of the radiographic set-up and focal spot size both affect image quality but are not considered in the reference radiographs).

1.2The X-ray film systems used in obtaining the illustrative data were as follows: Very Fine Grain (comparable to class I of Test Method E1815) and Fine Grain (comparable to class II of Test Method E1815).

1.3These reference radiographs2 consist of four composite illustrations3 and show how such factors as radiation energy, specimen thickness, and film properties affect the radiographic image. The reference radiograph films are an adjunct to this document and must be purchased separately from ASTM if needed.

1.4The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.5This 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.

1.6This 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.