BCGBC4018A Apply site surveys and set out procedures to building and construction projects

Project requirements

Two Peg Test

Before you start any project work your first task will be to carry out a two peg test to ensure your level is properly calibrated. Record in your field notes the process and state whether the test results are within the calibration limits..
Collimation error occurs when the collimation axis is not truly horizontal when the instrument is level. The effect is illustrated in the sketch below:

  1. Set out and mark on the ground (with wooden pegs driven into the earth, or roofing nails in tar) two point some 40 m apart. Set up the the level exactly mid-way (within 0.5m) between them.
  2. Take measurements of backsight and foresight for this first setup. The height difference DH will be free of the effects of collimation error.
  3. Next, move the level to a position just beyond the fore staff position (about 5m).
    The difference between the readings of the two level positions should be zero. If more than 5 mm the instrument need to be calibrated.
Instrument Level checking   (2 Peg test)

Setup and test the Instrument   ( Inst. No.________ )
                                                               0.0 m                  40.0 to 50 m       Difference

Recording from centre spot :        1 ________           2  ________         ________

Recording from 5 or 45 m spot :   1 ________           2 ________           ________

For each field exercise a level check is required.
This check must be carried out each time before you do any levelling.

Instead of the two peg test you may do a quick check close to the old survey store between G Block and F Block.

Project information

PROJECT 1(Two Peg Test)

PROJECT 2 (Grid levelling)

PROJECT 3 (Building set out)

Be careful when setting the Profiles. Please make sure you don't damage this equipment.

Please read 'How to set out a Building using profiles'.