SURVEY-II

​

TOPIC- TRIGNOMETRICAL SURVEYING AND TACHOMETRY

​

SUB/EXPT 2- DETERMINATION OF STADIA CONSTANTS

​

CIVIL ENGINEERING DEPARTMENT

BY

MR.BIKASH KUMAR DAS(LABB. ASST.)

AY:2021-2022

​

​

​

​

​

AIM OF THE EXPERIMENT – DETERMINATION OF STADIA CONSTANTS��

• Theory- In a telescope diaphragm is fixed infront of the eye piece.The diaphragm carries cross hairs is known as stadia.The telescope is focous by means of the focousing screw and may have either external focousing or internal focousing.
• In the external focousing telescope the diaphragm is fixed to the outer tube and the objective to the inner tube.
• By turning the focousing screw the distance between the object and diaphragm is altered tp form a real image on the plane of cross hair.
• From the theory D=(f/i) x s+(f+d)
• D=distance between vertical axis of telescope and staff,f=focal length,i=length of image,s=diff. of reading between lower and upper stadia,d=dist. Btwn optical center and vertical axis of telescope
• The quantity (f/i) is known as the multiplying const. and its value is usually 100.The quantity (f+d)is called additive const and its value is normally 0 but some time its value between 20 and 30 cm

​

• INSTRUMENT REQUIRED-1-Tacheometer (Digital/transit theodolite)

2-staff (telescopic staff/wooden staff)

3-tape-30m

4-peg 5-ranging rod

​

​

Conclusion- The equation are solved in pairs to gets several values of (f/i) and (f+d).The mean of the value is taken as the stadia const. of the corresponding instrument.

Video-

THANK YOU