using the rise and fall and height of collimation methods

• setting up, testing and using level ling devices
• undertaking closed and open traverses using arange of levelling equipment
• calculating distances using stadia lines.

 

Tool and equipment required to carry out levelling operation:

 

• Laserlevelsandtargets
• Levellingstaff
• Markingequipment
• Measuringtapesandrules
• Spiritlevelsandstraightedges
• Twoofthefollowing:
• Automatic/opticallevels
• Plumbbobs
• Waterlevels.

Materialrequirements

• Pegs
• Nails

Template 7: Height of collimation method

Height of collimation method
Station number	Backsight	Intermediate sight	Foresight	Height of collimation	Distance	Remarks

Template 8: Three-wire readings

Three-wire readings
Stations	Readings	Calculations
Station number: ___	To stadia line		Cross-hair accurate: Yes No
Cross-hair
Bottom stadia line
Station number: ___	To stadia line		Cross-hair accurate: Yes No
Cross-hair
Bottom stadia line
Station number: ___	To stadia line		Cross-hair accurate: Yes No
Cross-hair
Bottom stadia line

Template 9: Two-Peg test

Two-Peg test

Instructions:

1. Use pegs to mark the area on the worksite.
2. The points should be set up at a distance of 30m apart.
3. Depending on the exercise area, use pegs or a spray can to mark two points.
4. Set up the level instrument midway between the points.
5. Perform adjustment tests to ensure that the instrument is level.
6. Take and record the staff reading at each peg and record the level measurements in the table provided below.
7. Calculate the difference between the two readings and record it in the table.
8. Move the optical level so that it is 5 m outside one of the pegs.
9. Take the staff another reading and record them in the table.
10. Again calculate the difference between the two readings and record it in the table.
11. Check whether the readings are the same or not.

Calculations

Two peg test	Station A	Station B
Peg A
Peg B
Calculations
Results