1.1 X射线图像的图像质量和分辨率高度依赖于焦斑的特性。焦斑的成像质量基于从成像位置看到的其二维强度分布。 1.2 本试验方法提供了测定工业X射线管微型和微型焦斑的有效尺寸（尺寸）的说明。它基于欧洲标准EN 12543-5无损检测。无损检测用工业X射线系统中焦斑的特性。第5部分:微型和微焦点X射线管有效焦斑尺寸的测量。 1.3 本标准规定了一种通过边缘射线照片测量管电压高达225 kV（含225 kV）至300 μ m的X射线系统的有效焦斑尺寸的方法。应使用测试方法测量较大的焦斑 E1165 用针孔成像法测量工业X射线管焦斑的标准试验方法。 1.4 相同的程序可以在更高的千伏下使用，但测量的准确性可能较差。 1.5 以SI单位表示的值将被视为标准值。本标准不包括其他计量单位。 1.6 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践并确定法规限制的适用性。 1.7 本国际标准是根据世界贸易组织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的标准化原则制定的l贸易壁垒委员会。 ======意义和用途====== 5.1 影响射线照相图像的图像质量的因素之一是几何不锐度。几何不清晰的程度取决于辐射源的焦斑尺寸、源与待射线照相的物体之间的距离、待射线照相的物体与图像平面(胶片、成像板、数字检测器阵列(DDA)或射线照相检测器)之间的距离。该测试方法允许用户确定X射线源的有效焦斑尺寸（尺寸）。然后，该结果可用于建立源到对象和对象到图像检测器的距离，该距离适于维持给定射线照相成像应用的期望的几何不锐度或可能的最大放大倍数或两者。该方法的精度取决于成像系统的空间分辨率、放大倍数和所得图像的信噪比。

1.1 The image quality and the resolution of X-ray images highly depend on the characteristics of the focal spot. The imaging qualities of the focal spot are based on its two dimensional intensity distribution as seen from the imaging place. 1.2 This test method provides instructions for determining the effecting size (dimensions) of mini and micro focal spots of industrial X-ray tubes. It is based on the European standard, EN 12543–5, Non-destructive testing - Characteristics of focal spots in industrial X-ray systems for use in non-destructive testing - Part 5: Measurement of the effective focal spot size of mini and micro focus X-ray tubes. 1.3 This standard specifies a method for the measurement of effective focal spot dimensions from 5 μm up to 300 μm of X-ray systems up to and including 225 kV tube voltage, by means of radiographs of edges. Larger focal spots should be measured using Test Method E1165 Standard Test Method for Measurement of Focal Spots of Industrial X-Ray Tubes by Pinhole Imaging. 1.4 The same procedure can be used at higher kilovoltages by agreement, but the accuracy of the measurement may be poorer. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 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. 1.7 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 ====== 5.1 One of the factors affecting the image quality of a radiographic image is geometric unsharpness. The degree of geometric unsharpness is dependent upon the focal spot size of the radiation source, the distance between the source and the object to be radiographed, the distance between the object to be radiographed and the image plane (film, imaging plate, Digital Detector Array (DDA), or radioscopic detector). This test method allows the user to determine the effective focal spot size (dimensions) of the X-ray source. This result can then be used to establish source to object and object to image detector distances appropriate for maintaining the desired degree of geometric unsharpness or maximum magnification possible, or both, for a given radiographic imaging application. The accuracy of this method is dependent upon the spatial resolution of the imaging system, magnification, and signal-to-noise of the resultant images.