该欧洲标准通过锋利边缘的X线片确定了直到并包括500 kV管电压的X射线系统超过0.5 mm的焦斑尺寸。 X射线图像的图像质量和分辨率高度依赖于焦点的特征。焦点的成像质量基于物平面中的二维强度分布

This European standard specifies the checking of focal spot dimensions above 0,5 mm of X-ray systems up to and including 500 kV tube voltage, by means of radiographs of sharp edges. The image quality and the resolution of X-ray images depend highly on the characteristics of the focal spot. The imaging qualities of a focal spot are based on the two dimensional intensity distribution in the object plane.