Theodolite Traversing on survey and procedure

Theodolite Traversing on survey and procedure: 

What is Theodolite? Theodolite is used to measure the horizontal and vertical Angeles, It is recommended for more precise magnetic compass, This magnetic compass will help in measuring the angle up to an accuracy of 30, Along with this there is another tool which will measure the angle accuracy to 10, 20 using vernier theodolite. There are many theodolite types of the vernier, optic, electronic etc. Vernier theodolite is known as transmit, This transit theodolite has a telescope which can be rotated in a vertical plane.

Theodolite Traversing on survey and procedure:

Main parts involved in this theodolite are Levelling head and it is used to attach the instrument to a tripod and it will attach the plumb bob fixed along the vertical axis of the instrument. Main parts involved in this item are an (18): an annular horizontal plate with the graduations provided all around, from 0 to 360°, in a clockwise direction. The graduations are in degree divided into 3 parts so that each division equals to 20 min. Main things to remember are when the verticle circle of the theodolite is on right side of the observer, this position is named as face right and observation made is called face right observation.

Theodolite Traversing on survey and procedure

Depending upon the position you kept there are different terminology to use like Face Left, Telescope Normal, Telescope Inverted. while setting the instrument you need to be careful on maintaining the levelling, Focussing will mean a lot as well, Focussing the eyepiece, Focussing the objective, depends on two methods Repetition method and Reiteration method.

Errors you will come across while setting up this Theodolite Instrument are:

• Non-adjustment of plate bubble
• Line of collimation not being perpendicular to horizontal axis
• Horizontal axis not being perpendicular to vertical axis
• Line of collimation not being parallel to axis of telescope
• Eccentricity of inner and outer axes
• Graduation not being uniform
• Verniers being eccentric
• Personal errors
• Natural errors
• High temperature causes error due to irregular refraction.
• High winds cause vibration in the instrument, and this may lead to
• wrong readings on verniers

There are two types of Surveying in Civil Engineering like:

• Closed Traverse
• Open Traverse

Methods involved in Traversing are:

• Chain traversing 
• Chain and compass traversing 
• Transit type traversing a)By fast needle method b)By measurement of angles between the lines
• Plane table traversing