Mirror compensators of the tilt on simple non-multipliable pendula in self-consistent levels
© Lensky O.V.
Mirror compensators of self - aligning level tilts are considered which act in convergent beams behind the level's lens. Geometrical properties of one-parameter family of the principal rays reflected by flat mirror swinging as a simple nonmultiplying pendulum are investigated. Tilt angle of the level serves as a parameter (with accuracy to additive constant). In general case envelope of the straight lines family is a circle on which foci of limitingly thin pencils of the lines lie. From the standpoint of possible expansion of compensated tilts angnlar range degeneration of the circle into a point (id est transformation of the family into homocentrie beam of the rays) is advantageous. It is shown that the family of straight lines changes into homocentric beam only in two cases: (1) when mirror plane contains the axis of pendulum swinging and (2) when mirror reflects incident principal ray backward along the ray itself. Explicit expression of the angle error of compensation is obtained in terms of the pendulum compensator's parameters and the tilt angle to be compensated. The paper contains some recommendations and formulae useful in optical design of the self-aligning levels with mirror compensators.