When the telescope optical axis isnt perpendicular to the platform rotary axis strictly,the image that is caused by reflecting via double-face flat speculum of the bright cross will have some changes.

• 深入分析分光计的望远镜光轴与载物台旋转轴不严格垂直时出现的望远镜筒中的亮十字物经载物台上的双平面镜所反射的十字物的像的变化;简述准确快速调节望远镜光轴与载物台旋转轴严格垂直的方法。