MPSC CIVIL ENGINEERING 2020

Q78. Total Station is a combination of :-

1. Theodolite and compass
2. Theodolite and EDM
3. Electronic theodolite and EDM
4. Electronic theodolite and Digital planimeter. 

Ans :- 3

Soluttion:-

 

The most commonly used survey instrument today is total station. A total station is the combination of electronic theodolite, an electronic distance measuring device (EDM) and microprocessor with memory unit.  A fully charged battery works for about 3 to 5 hrs continuously.The Electronic digital theodolite first introduced in 1960 by carl zeidd etc.The basic properties are unsurpassed range, speed and accuracy of measurements. Total stations are developed in view of the maximal convenience of work of the user. High-efficiency electronic tachometers are intended for the decision. Data can be downloaded from the total station to a computer and application software used to compute results and generate a map of the surveyed area.

Accuracy of a Total Station:-

Accuracy depending upon the instrument and varies from instrument to instrument

1.The angular accuracy varies from1″ to  20 ″.

2.Distance accuracy depends upon two factors.

Instrumental error which ranges from

+ / – 10mm to + / – 2mm.

b) Error due to the length of measurement.

It can be from + / – 10mm to + / – 2mm per kilometre.

1 prism, 2.5–2.7 km2 prisms

5-7 km3 prisms

Total station can be used :-

• When two points are given.
• When only one co-ordinate is given. In this case the coordinate of the back station is determined by any suitable method.
• When no co-ordinates were given in which case arbitrary system of coordinates can be used.

Functions of Total Stations :-

Following are the various function of total station :-

• Averaging multiple angle and distance measurements.
• Making curvature and refraction corrections to elevations determine by trigonometric levelling.
• Reducing slope distances to their horizontal and vertical components.
• Correcting electronically measured distances from prism constant, atmospheric pressure, and temperature.
• Computing coordinates of survey points from horizontal angle and horizontal distance.

Application of total station:-

There are various following application of Total station:-

• Detail survey i.e., data collection.
• Height measurement (Remove elevation measurement- REM).
• Control Survey 
• Area calculations, etc.
• Remote distance measurement (RDM) or Missing line measurement (MLM).

Instruments of total station :-

The various instruments used in Total station :-

The EDM instrument component installed in a Total Station is relatively small but still has distance ranges adequate for most work.  Lengths up to about 2 km can be measured with a single prism, and up to about 6 to 7 km with triple prism.

The angle resolution of available Total Stations varies from as low as a half-second for precise instruments suitable for control surveys, up to 20″ for instruments made specifically for construction stakeout .