Surveying ppt : COMPONENETS OF TRANSIT THEODOLITE

: COMPONENETS OF TRANSIT
THEODOLITE

1. Topic : COMPONENETS OF TRANSIT THEODOLITE

2. GROUP OF STUDENT: Name Enrollment Number Prajapari Himanshu k. 140120106085 Patel Rahul 140120106088 Raithatha Nilesh 140120106089

3. INDEX INTRODUCTION Definition MAIN COMPONENETS OF A TRANSIT THEODOLITE

4. INTRODUCTION Theodolite is a basic surveying instrument which is use for measuring vertical and horizontal angle. Theodolite is more precise than magnetic compass. Magnetic compass measures the angle up to as accuracy of 30’. However a vernier theodolite measures the angles up to and accuracy of 10’’, 20”

5. Definition A transit theodolite is one in which the telescope can be revolved through a complete revolution about its horizontal axis in a vertical plane.

6. Main Components of Transit Theodolite 1. Trivet 2. Foot Screws 3. Tri Branch 4. Leveling Head 5. Spindles 6. Lower Plate 7. Upper plate 8. A Frame 9. T Frame 10. Altitude Bubble 11. Compass 12. Tripod

7. 1. Trivet It is a circular plate having a central, threaded hole for fixing the theodolite on tripod stand. It is also called the base line.

8. 2. Foot Screws Lower part – The Trivet Upper Part – It is passes through the threaded hole in the tribrach plate. Foot screws is used for leveling the instrument.

9. 3. Tri Branch The upper parallel triangular plate carrying three foot screws at its ends is called the Tri branch. 4.Levelling Head . It is consists of two parallel plates separated by the 3 leveling screws.

10. It gives support the upper part of the instrumental and attaches it to the tripod

11. 5. Spindles & Clamp 1. Inner spindle 2. Outer Spindles The inner axis is solid and conical and the outer spindle is hollow.

12. 6. Lower Plate an annular horizontal plate with the graduations provided all around, from 0 to 360°, in a clockwise direction. The graduations are in degree divided in to 3 parts so that each division equals to 20 min. Horizontal angles are measured with this plate. The size of the theodolite is defined by the diameter of horizontal circle.

13. 7. Upper plate Horizontal plate of smaller diameter provided with two venires. on diametrically opposite parts of its circumference. They are used to read fractions of the horizontal circle plate graduations. The venires are graduated in 20 min and each minute is divided in 3 to 5 parts making least count 20” or 10”.

14. 8.‘A’ Frame or Standard Two frames are provided on the upper plate to support the telescope, the vertical circle and vertical vernier scale. These frame are known as standard or A-frame.

15. 9. T Frame or Index bar It consists of a vertical leg known as clipping arm and a horizontal bar called the index arm engraved with venires C and D at its ends.. It is used as seat for altitude bubble and also provides vernier reading for vertical angle measurement

16. 10. Altitude Bubble A sensitive level tube called altitude bubble, is attached to the top of the T- frame. This bubble is brought to the center by the clip screw. A mirror is provided on the top of bubble.

17. 11. Compass Sometimes a circular box compass is mounted on the vernier scale between the standards. It is provided for taking the magnetic bearing(W.C.B) of line

18. 12. Tripod The theodolite is mounted on a strong tripod when being used in the field. The legs of the tripod are solid or framed. At the lower ends of the legs, pointed steel shoes are provided to get them pushed into ground. The tripod head has male screws on which the trivet of the leveling head is screwed.

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