1.1 本文件描述了射线照相图像的外观，其中图像质量的基本成分发生了变化，即变量，例如是否使用了X射线或伽马射线源，射线照相胶片的特性（梯度、粒度和显影条件）和增感屏，和试样厚度（射线照相装置的几何结构和焦点尺寸都会影响图像质量，但在参考射线照片中未考虑）。 1.2 用于获得说明性数据的X射线胶片系统如下:极细颗粒（与试验方法的I级相当 E1815 )细颗粒（与试验方法II级相当 E1815 ). 1.3 这些参考射线照片 2. 由四个合成插图组成 3. 并说明辐射能量、试样厚度和胶片特性等因素如何影响射线照相图像。 参考射线底片是本文件的附件，必要时必须从ASTM单独购买。 1.4 以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 任何射线照相系统的关键考虑因素是其对比度分辨率和空间分辨率能力（即灵敏度）。给定系统可获得的灵敏度程度取决于几个射线照相参数，如源能级、胶片系统等级、增感屏的类型和厚度以及射线照相的材料厚度。这些参考射线照片允许用户估计当这些参数与特定技术不同时可能获得的灵敏度变化程度。本标准也可与试验方法一起使用 E1815 或者通过练习 E746 或试验方法 E1735 为开发用于评估用户特定系统的数据提供基础。该数据可以帮助用户确定适当的参数，以获得所需的射线照相系统灵敏度。

1.1 This 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). 1.2 The 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 ). 1.3 These reference radiographs 2 consist of four composite illustrations 3 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. 1.4 The 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. 1.5 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. 1.6 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. ====== Significance And Use ====== 4.1 A key consideration with any radiographic system is its contrast resolution and spatial resolution capability (that is, sensitivity). The degree of obtainable sensitivity with a given system is dependent upon several radiographic parameters such as source energy level, film system class, type and thickness of intensifying screens, and material thickness radiographed. These reference radiographs permit the user to estimate the degree of sensitivity change that may be obtained when these parameters are varied from a specific technique. This standard may also be used in conjunction with Test Method E1815 or with Practice E746 or Test Method E1735 to provide a basis for developing data for evaluation of a user's specific system. This data may assist a user in determining appropriate parameters for obtaining desired degrees of radiographic system sensitivity.