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Tuesday, August 18, 2020

SELECTION OF SURVEY STATIONS


SELECTION OF SURVEY STATIONS

The following points should be remembered during the selection of survey stations:

  1. The stations should be so selected that the general principle of surveying may be strictly followed.

  2. The stations should be intervisible.

  3. The stations should be selected in such a way that well-conditioned triangles may be formed.

  4. The base line should be the longest of the main survey lines.

  5. The survey lines should be taken through fairly level ground, as far as practicable.

  6. The main survey lines should pass close to the boundary line of the area to be surveyed.

  7. The survey lines should be taken close to the objects so that they can be located by short offsets.

  8. The tie stations should be suitably selected to fix the directions of adjacent sides.

  9. The subsidiary stations should be suitably selected for taking check lines.

  10. Stations should be so selected that obstacles to chaining are avoided as far as possible.

  11. The survey lines should not be very close to main roads, as survey work may then be interrupted by traffic.

TYPES OF EQUIPMENTS FOR CHAIN SURVEY

The following equipment is required for conducting chain survey:

  1. Metric chain (20 m)                             =          1 no.
  2. Arrows                                                 =          10 nos. 
  3. Metallic tape (15 m)                            =          1 no. 
  4. Ranging rods                                       =          3 nos. 
  5. Offset rod                                            =          1 no. 
  6. Clinometer                                          =          1 no.
  7. Plumb bob with thread                        =          1 no.
  8. Cross staff or optical square               =          1 no.
  9. Prismatic compass with stand            =          1 no. 
  10. Wooden pegs                                      =          10 nos. 
  11.  Mallet                                                  =          1 no.
  12. Field book                                           =          1 no.
  13.  Good pencil                                        =          1 no.
  14. Pen knife                                             =          1 no.
  15. Eraser (rubber)                                    =          1 no.

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