本欧洲标准规定了通过锐利边缘的X光片测量焦点尺寸在5到300um范围内直到并包括225kV管电压的X射线系统的方法。 X射线图像的图像质量和分辨率高度取决于焦点的特征。焦点的成像质量基于物平面中的二维强度分布。为了认证，使用射线照相技术

This European Standard specifies a method for the measurement of focal spot dimensions within the range of 5 um to 300 um of X-ray systems up to and including 225 kV tube voltage, by means of radiographs of sharp edges. 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 the two dimensional intensity distribution in the object plane. For certification purposes the radiographic technique is used.