为了更好地了解和掌握我们手中使用的X射线探伤机的性能,有必要对其焦点所在的位置、大小、几何形状进行测定。这里介绍一种简单易行的测定方法。这种测定方法是依据小孔成像的原理。通过焦点在底片上形成的像我们可以清楚地看到焦点的真实形状。通过所成像的大小以及小孔、底片、X光机间的相对距离即可计算出X光机焦点的位置和尺寸 In order to better understand and grasp the performance of the X-ray flaw detector used in our hands, it is necessary to determine the position, size and geometry of the focus. Here is a simple and easy method of determination. This method of measurement is based on the principle of pinhole imaging. Through the focus on the film formed on the image we can clearly see the true shape of the focus. Through the imaging of the size and the hole, the film, the relative distance between the X-ray machine can calculate the position and size of the X-ray machine focus