1. Surveying Instrument Basics ©2004 Dr. B. C. Paul

2. Basics of Surveying –Surveying creates a one to one correspondence of points in the field to points on a map or plan

3. Why is This Important? Property line boundaries –We need to know them above ground –And Underground –Define ownership of reserves and locations where buildings can be put Location of Ore Bodies and High and Low Grade Ore –Can be a disaster if you dig in the wrong place Location of Blast Holes and Patterns Need to control haul roads and bench grades Need to control direction and separation of tunnels and cross-cuts

4. More Needs Need permit and regulatory controls –Have to report surface and underground structures –Grades and topography Need to measure cut and fill volumes and stockpiles Need to control buildings and structures to be on the level

5. How Do We Survey –Done by starting with a known point and direction Measuring angles and distances and using trig to figure out the location of other things Known Point Known Direction But Where is This Point?

6. Plane Surveying Can Use Simple Trig to Figure the Coordinates of the new point –To Use Trig We Have to Suppose We Are Surveying on a flat surface –The Little White Lie The Earth is Flat We only get busted in surveying over long distances. Most Traditional Surveying is based on measurement of distance and direction and instruments are designed for these two functions.

7. Distance Measuring Devices Traditional Way was a surveyors chain. Still call physical measuring “Chaining”

8. Other Distance Measurements Steel Tape –May have tensioning scales for pulling tight to control expansion and sag Cloth Tape for lower precision work Are Optical Alternatives to physical measurement today.

9. Angle Measuring Devices Transits Theodolites Levels

10. Surveying Assumptions Surveys are done on a level plane that is tangent to the earths surface in the area of the survey –This implies that the instrument must be level Instrument comes with leveling screws –Turn clockwise to tighten (raise that side) –Turn counter clockwise to loosen (Lower that side) –Turn the screws in pairs to avoid torqueing and damaging your instrument

11. Leveling the Instrument Set instrument legs so instrument is about level –Often have a single bubble type level to get this crude adjustment. Often have two bubble levels at 90 degrees to each other Instruments have either 3 or 4 leveling screws

12. Leveling with 4 screws Aim the telescope down the line with one of the sets of leveling screws –Use two in line screws to set level in that direction –Turn 90 and line with the other set and level With two bubble levels may not have to turn With 4 screws the two directions of the plane can each be worked of independently Normally still turn and check the level in several directions

13. Leveling with 3 screws Line telescope with one pair –Level along one axis Turn scope to perpendicular to first pair and lined up with 3 rd –Now use that screw alone to level in that direction Common practice to do crude in one direction, crude in the other and then turn back to first direction and do precise and precise

14. It Proficiency #1 Time You Get to Level an Instrument with 3 screws And an Instrument with 4 Screws