MEASUREMENT OF VERTICAL ANGLE
To determine the vertical angle between the top and the bottom of the building and also find the height of the building.
(ii) Tripod Stand
(iii) Chain (or) tape
· The instrument fixed over the station and levelled with reference to the alidade bubble.
· The vertical circle vernier is fixed at zero.
· The vertical circle clamp screw is loosen and the telescope is directed towards the top of the object ‘A’ and Sighted. The vertical circle reading is noted.
· Now the telescope is direct towards the bottom ‘B’ and the sighted using tangential screw of the vertical circle.
· The distance between the building and instrument station ‘P’ is measured using chain (Or) tape.
· Then the height of the building is calculated by using the trigonometrically relations.
Thus the height of the building is found to be ---------------