Levelling Instruments
A level is an instrument giving horizontal line of sight and magnifying the reading at a far away distance. It consists […]
Surveying is the art of making measurements of objects on, above or beneath the ground to show their relative positions on paper. The relative position required is either horizontal, or vertical, or both. Less precisely the term Surveying is used to the measurement of objects in their horizontal positions. Measurements to deteremine their relative vertical positions is known as levelling.
A level is an instrument giving horizontal line of sight and magnifying the reading at a far away distance. It consists […]
Along with a level, a levelling staff is also required for levelling. The levelling staff is a rectangular rod having
The following methods are used to determine the difference in elevation of various points: (i) Barometric levelling (ii) Hypsometric levelling
The following terms are used in direct method of levelling: (i) Plane of Collimation: It is the reduced level of
The adjustments to be made at every setting of the instrument are called temporary adjustments. The following three adjustments are
At any point, if bearings of any two lines are known, the angle between these two lines can be easily found
The following are the different types of direct levelling: (i) Simple levelling (ii) Differential levelling (iii) Fly levelling (iv) Profile
The magnetic meridian and the true meridian may not coincide with each other in a place. The horizontal angle between these
A freely suspended and properly balanced magnetic needle is expected to show magnetic meridian. However, local objects like electric wires
In compass survey chain or tape is used for linear measurement. If the surveying starts from a station, goes round