A securing system for transporting and mounting a measuring instrument for the determination of a position of two components which are movable in relation to each other. The securing system including a securing device and a support body having a guide track and supporting a linearly extending measuring graduation. The securing device includes a base body, which is longitudinally displaceable along the guide track of the support body and can be fixed in place on the support body by clamping forces in order to maintain the mounting base in a desired position in regard to the support body. The securing device further includes a clamping element pivotably seated on the base body about a pivot axis, which has an eccentric surface, which is embodied to be eccentric with respect to the pivot axis, and that, by pivoting the clamping element, the eccentric surface can be brought into engagement with the support body in such a way that, in the course of pivoting of the clamping element, the base body is fixed in place on the support body and can be brought into a state in which it is displaceably seated on the support body.