Determination of the distances by the DD5 by the rangefinder is made in the following order: 1. The average horizontal thread of the pipe threads is led to the zero touch of the Nonius Reiki. 2. Turning a micrometerated screw, the pipe is tilted until one of the strokes of Nonius is compatible with the bar of the rail scale. In this case, it is necessary to ensure that the middle thread does not go beyond the divisions and checkers of Nonius. 3. The countdown develops: the number of divisions of the rail to zero vernier 110, 0. The numbers of the coincided stroke of Nonius plus the number of Nonius divisions and their shares passed by a horizontal thread at the first combination of 2, 45. The same, with the second combination 2, 48. When determining the angle of inclination to bring the measured distance to the horizon, the middle thread is shown to the coincident nonius and the angle of inclination is led to the bisector of the parallactic angle. Reduction rangefinders automatically lead to counts on the rail to the values corresponding to the horizontal laying of the ray of visualization. The most successful and constructively simple solution was received. TO. Imperfect, using a freely suspended optical wedge for this purpose.