1.1 本《可获得等效透度计灵敏度指南》涵盖了1 T 和2 T 在使用工业X射线胶片的一些实际射线照相条件下，孔是可见的。这些值表示平板的接近最佳灵敏度。射线照相条件下，样品的散射累积值或图像平面上的后向散射辐射值较高，则灵敏度较低。 1.2 作为本指南的附件，包括八张说明实用射线照相系统可获得灵敏度的射线照片，必须从ASTM购买。 1.3 单位- 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。 1.4 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。 1.5 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、曝光（密度），等。本指南允许用户在使用规定的一组射线照相参数时，估计X射线和钴-60γ射线可能获得的灵敏度。本指南也可与实践结合使用 E746 或 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。这种方法的另一种替代方法是使用第节中详述的辅助射线照相插图 6. .

1.1 This guide to obtainable equivalent penetrameter sensitivity covers the minimum penetrameter thicknesses for which the image of the 1 T and 2 T holes is visible for a few practical radiographic conditions using industrial X-ray film. The values represent near optimum sensitivity for flat steel plates. Radiographic conditions that give higher values of scatter buildup from the specimen or backscattered radiation at the image plane will give poorer sensitivity. 1.2 Eight radiographs that illustrate sensitivities obtainable with practical radiographic systems are included as adjuncts to this guide and must be purchased from ASTM. 1.3 Units— 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. 1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 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, exposure (density), etc. This guide permits the user to estimate the degree of sensitivity that may be obtained with X-rays and Cobalt-60 gamma rays when using a prescribed set of radiographic parameters. This guide may also be used in conjunction with Practices E746 or 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. An alternate to this approach is the use of those adjunct radiographic illustrations detailed in Section 6 .