Displacement of spying axes

Turn the pipe in a vertical plane on a certain corner. Vizier axes will cross the rail at points, the images of which will coincide with the thread of the grid, just as points used to coincide with it. At the same time, the displacements of the visir axes relative to the rails will be equal to each other. However, the segment is considered through the wedge system, the increase in which, therefore, it will be visible increased and, therefore, when the points A and B are not coincided in the field of the visual pipe. Therefore, when turning the pipe, we will observe not only the movement of the two images of the rail relative to the thread of the net, but also the displacement of these images relative to each other. In the general case, when counting the distances along the rail using Nonius, none of the strokes will definitely coincide with any barrel of the rail. The interval between the stroke of Nonius and the stroke of the rail scale can be determined by the formula. For this, these strokes are preliminarily combined with the rotation of the pipe and measure the size of the thread movement along the nonius scale. In accordance with this, two -sided wooden rails with invar ribbons stretched on them, on which scales with two centimeter divisions and Nonius scales are applied to the set of the DDZ. One side of the rail is digitized from before, and the other from before. Reiki are installed on a separating stand 0.5 high, and each of them is supplied with two supports, the lengths of which are regulated by rotation of the handles. The installation of rails in a vertical position is carried out using round levels. The presence of a shift A allows you to combine two important functions in the DDZ: creating a constant parallactic angle and measuring the size of the basis (a hundred times more accurate than with the usual use of nonius).