The operating requirements of the spirit level tool

Between two unknown points of the spirit level tool, open the tripod, take out the level from the instrument box, place it on the tripod, level it with three base screws, center the round bubble, and follow the leveling tube level. The horizontal brake handwheel is leveled. It is reflected through the triangular prism in the horizontal mirror, and the horizontal overlap is horizontal. Align the telescope with the tower ruler on the unknown point 

(1)(spirit level tool)Align the tube level again, read the reading of the tower ruler (rear view), rotate the telescope to the tower ruler at the unknown point 

(2)(spirit level tool)Adjust the tube level, read the reading of the tower ruler (front view), and record it in the record book.

Calculation formula of the spirit level tool: height difference between two points = rear view - front view.
​