The document describes the main components of a transit theodolite. It lists 12 key components: 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, and 12) tripod. The lower plate measures horizontal angles with graduations from 0 to 360 degrees. The upper plate has two verniers used to read fractions of degrees on the lower plate. The tripod supports the theodolite during field use.

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”

6. 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.

7. 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

8. 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.

9. 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.

10. 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.

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

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

13. 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.

14. 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”.

15. 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.

16. 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

17. 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.

18. 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

19. 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.

20. Thank
You….