To solve the problems with the measuring of the verticality of oil well pump liners, a simple measuring meter is designed.为解决抽油泵衬套垂直度测量较困难的问题，根据抽油泵衬套的特点，设计了抽油泵衬套垂直度简易测量仪。
In view of the requirements of the verticality and parallelity in the process of equipping elevator for high building, a new laser collimating system is presented.针对高层建筑电梯安装过程中导轨垂直度与平行度的要求，设计了一种新型的激光准直系统。
