Geodetic Rod

a metal rod 1-3 m long that gives a physical representation of an accepted basic unit of measure of length or its multiples. Since it is a standard measure of length, the geodetic rod is used to store and reproduce a linear measure of length and also to check and determine the length of working measuring instruments that are part of the set of basis instruments. End-plate geodetic rods were formerly used (the length of the measure was determined by the distance between the surfaces of its ends); modern geodetic rods are hachured (the length of the measure and its multiples or fractions are marked by appropriate hachures on the polished neutral surface of the rod).