The non diffracting beam is used as the measuringbeam and a virtual detector is used to expand detector size.
该系统用无衍射光作测量光束，用虚拟探测器扩展探测器尺寸。
2
TEMs work by firing a beam of electrons through the material and measuring how it absorbs and deflects the particles to build up an image of the sample.
TEMs 的工作原理是通过发射一束电子穿过某种物质，并测量它如何吸收和偏转粒子来建立样本的图像。
3
However, in practice, the excursion, transmission refraction and optics aberrance of the laser beam will affect the measuring precision.