三种投影垂直面的一种。
在同一铅垂面内，当视线在水平线上方时，视线与水平线的夹角。
Trying on drilling with high water level and large elevation angle;
传统的接触式测量方法很难实现由多个非连续铅垂面形成大平面的平面度的检测。
Its very difficult to achieve the flatness detection of the large flat surface formed with several non-continuous vertical planes with traditional contact measurement.
应用推荐