The reticle is engraved with vertical division, horizontal division and line-of-sight division. The horizontal and vertical divisions have a small grid value of 5 mils and a large grid value of 10 mils. The line-of-sight division is designed with a height of 2m to be measured. The measurement range is from 400m to 2000m. Within 1000m, the line-of-sight division is 50m per small grid value, and each large grid value is 100m. In 1000m to 2000m, each small grid The value is 100m and the value of each large grid is 500m.

1. Hang the plane mirror on the telescope eyepiece and observe the reflected image. At this time, if the image is clear, and the slightly oscillating head and the crosshair are not parallax, it means strict coplanarity.

2. It can be changed not only to make the optical axis of the telescope perpendicular to the axis of the instrument, but also to make the optical axis of the telescope parallel to the optical axis of the stage.

3. If there is no effect to start reading, if you have started reading, you have to do it again.

4. It is due to the tilt of the telescope and the tilt of the stage. Because if the plane mirror is not tilted, the tilt of the plane mirror before and after turning 180 does not change, and the reflected image should be at the same position. The plane mirror is tilted, assuming that the front of 180 is upright, like the upper side, it is tilted after 180 degrees, like the semi-adjustment method used below.