Pole

The range pole is used by the surveyor and civil engineer to set up the theodolite centrally and with millimeter precision over the survey point .

Poles are made of light metal and can be telescoped out. They replaced the previously used sinker (sinker, Plumb ), which by swinging or centering wind would take longer.

After setting up the tripod , the range pole is attached to the heart screw from below and extended to the point on the ground . Then the tripod or the theodolite substructure is moved until the circular level is on the pole. In addition, the exact instrument height above the point can be read off (and, if necessary, also adjusted).

An alternative is centering with the optical plummet , which is built into the base plate of most measuring devices . It allows more precise settings, but they take a little longer. It is also necessary to adjust the optics from time to time .

See also: centering