What is theodolite || Parts of theodolite || Surveying Function of theodolite, parts of theodolite

Theodolite Surveying * Theodolite is used for measuring horizontal and vertical angles. It may be used for prolonging a line, levelling and even for measuring distances indirectly (tacheometry). * Main parts of a theodolite are telescope, vertical circle, vernier frame, standards (A-frame) upper   plate, lower plate, plate level, levelling head, magnetic compass, tripod, plumb hob and shifting head. * Fundamental axes of theodolite are: 1. Vertical axis 2. Trunnion axis 3. Line of collimation 4. Altitude level axis 5. Axis of plate level A theodolite is said to be in proper condition, if the following conditions are satisfied: 1. The axis of the plate is perpendicular to the vertical axis. 2. The trunnion axis is perpendicular to the vertical axis. 3. The line of collimation is perpendicular to the trunnion axis. 4. The axis of the altitude level is parallel to the line of collimation. * Temporary adjustment involves setting up, levelling and focussing. * To get more accurate resul...