经纬仪主要是用来测定水平用和垂直角的。它的结构比较复杂，其中度盘是经纬仪的重要光学元件。度盘偏心直接影响着经纬仪的校正。度盘偏心差是指度金的刻划中心与度盘的旋转中心不重合而产生的偏差。度盘偏心的校正，通常是借助于专门的度金偏心校正促进行的。这里仅以经纬仪 Theodolite is mainly used to determine the horizontal and vertical angle. Its structure is more complex, of which the dial is an important optical element of theodolite. Degree of disc eccentricity directly affects the theodolite calibration. Deviation eccentricity refers to the degree of gold scoring center and the rotation of the dial center does not coincide with the deviation. Degrees of correction disk, usually by means of a special degree of gold eccentric correction to promote the line. Here theodolite only