1. TRANSIT THEODOLITE

2.  A theodolite is a precision optical instrument for
measuring angles between designated visible points
in the horizontal and vertical planes.

3. CLASSIFICATION OF THEODOLITE
THEODOLITE
BASE ON ANGLE
BASE ON HORIZONTAL AXIS
Transit theodolite
Non transit theodolite
Vernier theodolite
Micrometer theodolite
Electronic digital
theodolite

4. MAIN COMPONENTS OF TRANSIT THEODOLITE
1. Trivet
2. Foot screws
3. Tri branch
4. Leveling head
5. Spindels
6. Lower plate
7. Upper plate
8. A frame
9. T frame
10. Altitude bubble
11. Compass
12. Tripod

5. PARTS OF TRANSIT THEODOLITE

6. 1. Navigating
2. Meteorology
3. Laying out building corners and lines
4. Measuring and laying out angles and straight lines
5. Aligning wood frame walls
6. Forming panels
7. Plumbing a column or building corner
APPLICATION

7. Repeat readings are unnecessary.
Greater accuracy.
Internal magnifying optical system.
Electronic readings.
Horizontal circles can be instantly zeroed or set to any other value.
Horizontal circle readings can be taken either to the left or right of
zero.=
ADVANTAGES OF USING A TRANSIT THEODOLITE

8. DISADVANTAGES OF USING A TRANSIT THEODOLITE
It is not intended for very accurate work.
It is not suitable in monsoon.
It is essentially a tropical instrument.
Due to heaviness, it is inconvenient to transport.
Since there are so many accessories , there is like hood of them being lost.

9. Instrumental errors
Upper and lower plate adjustment is imperfect
Line of collimation and telescope axis not parallel.
Line of collimation not perpendicular to horizontal axis of theodolite.
Personal errors
Errors due to leveling
Inaccurate centering of theodolite instrument over station mark point.
Error due slipping of lower plate of theodolite instrument. This errors occur when
foot screw is not tight.
Taking reading wrong from vernier scale.
Natural errors
Due to high temperature refraction error occur.
Movement of tripod leg due to wind
ERRORS