The relation between the displacement of the turning edge in two perpendicular directions of turning plane and the positions of diffraction dark fringes can be determined and it can be used to calculate the small rotating angle.

• 通过导出转动棱边在转动平面内2个相互垂直方向上的位移与观察屏上衍射暗纹位置间的关系式,并利用它对转动棱边的转角进行计算。