Hi,
Total Station(TS) is a surveying instrument used to find the direction angles and distances of various lines. In this post, you will learn how to operate a Total Station. But first, let’s know the components of a TS.
Components
These images show the components of TS. The carrying handle can be fixed using to handle tightening screws. The sighting collimator is used for the rough sight of the prism. The Eyepiece is used for sighting the prism. Together with the eyepiece is telescope holding grip which is used to transit the telescope.
All these are shown in the image below. Telescope holding grip is used for transiting the telescope, and telescope focusing knob is used to clear the image on the diaphragm.
There is a vertical tangent screw used for the small vertical movement of the TS, so as to get the clear and straight line of sight, and hence the crosshairs intersect the prism. Also, there is a vertical motion clamp used to fix/lock the position of the vertical tangent screw.
Similarly, there is a horizontal tangent screw and a horizontal motion clamp, which is used to control the horizontal rotation of the TS.
There are two display units, and the keys adjacent to them. The optical plummet screw is used to sight the ground and is used to level the TS.
There are three levelling screws in the tri-bach which is fixed using the tri-bach fixing lever.
When you power on the Display unit, it gets into its default mode – i.e.angle measurement mode. Display unit uses dot matrix LCD, which has four lines(rows) and 20 characters per line. The upper three lines display the measured data, and bottom line displays the softkeys’ functions which change with the measuring mode.
The image shown above shows all the keys with their respective functions.
Centering
Now before we take any measurements, it is important to do the centering of the TS and the prism. It is done as explained below.
Step.1 Level the Total Station(TS)
Put the Total Station on the Tripod Stand. The approximately level the lower bubble by arranging the three legs of the tripod stand.
Then note that there is a horizontal bubble tube, in which the bubble will not be at centre if the total station is not levelled.
Bring this bubble tube parallel with the imaginary line joining two of the three screws. And then rotate both of them together either inwards or outwards. Note the movement of the bubble and rotate the screws until the bubble comes to the centre.
Now rotate the total station such that the bubble tube is perpendicular to that imaginary line between the two screws. When you do so, the bubble may move from the central position, so now rotate the third screw until it again comes to the centre. Now bring the tube to the initial position and again check the bubble and repeat the process until the bubble is at the centre in both of the positions.
Now your Total Station is Levelled.
Step.2 Put the Stand and Prism at the station of interest and Level it
There is a stand and a prism which is sighted from the TS. Fix the prism on the stand, and note that there a bubble on the stand too, so you have to level the stand too.
Simply fix the vertical position of the stand until the bubble is centred. Now sight the TS through the sighting collimator.
Taking Measurements
Now that centring is done, let’s take the measurements to find the horizontal distance between two points.
Horizontal Distances, slope distance, co-ordinates and angle Measurement using Total Station.
The two points, of high interest, one – where the instrument is set up and the other where the prism is set. Use the sighting collimator to do the approximate bisection of the prism.
Then sight through the eyepiece and use the focussing screw to bisect the prism with the crosshairs. Then tighten up the vertical tangent screw using the vertical tangent clamp.
Use the eyepiece to get a clear prism image. Once it is done, click on the distance measurement mode key.
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| Display Unit of Total station showing the Slope Distance(SD) |
Similarly, when you click on the co-ordinate key, it will show the coordinates (x,y,z) of the station. And when it is in angle measurement mode, it will display horizontal angle with the right face(HR) and vertical angle(V.)
Thanks!
