Civil Engineering Surveying: Levelling Part 2

Flashcards covering key concepts from the lecture on Civil Engineering Surveying and Levelling.

Levelling

A surveying technique used to determine the elevation of points on the ground.

Closed Level Traverse

A series of level runs from a known Datum or Reduced Level (RL) back to a known Datum.

Misclosure

The difference between the measured height difference and the known height difference.

Collimation Error

An error due to the line of sight not being perfectly horizontal.

Two-Peg Test

A field calibration procedure to determine and reduce collimation error in level instruments.

Back Sight (BS)

The first reading taken after setting the instrument, taken at a point of known elevation.

Fore Sight (FS)

The last reading taken before moving the instrument, taken at a point of unknown elevation.

Temporary Benchmark (TBM)

A self-made point which has a transferred value of reduced level (RL).

Height of Collimation (HOC)

An alternative method for calculating using the height of the collimation.

Arithmetic Checks

Verifications done to ensure the calculations for levelling are accurate.