Tacheometric surveying. Tacheometer. Tacheometer is transit theodolite fitted with stadia diaphragm, and analltic lens.
Tacheometer is transit theodolite fitted with stadia diaphragm, and analltic lens
Anallatic lens: Additional convex lens is provided between the eye piece and the object glass at a fixed distance from the object glass. The purpose of providing anallatic lens is to make additive constant (f+d) exactly zero.
The stadia readings with horizontal sight on a vertical staff held 50 m from a tacheometer were 1.285 m and 1.780 m. the focal length of the object glass was 25 cm. the distance between the object glass and the vertical axis of the tacheometer was 15 cm. calculate the stadia interval.