Chapter 6 - Intro to Leveling
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Transcript of Chapter 6 - Intro to Leveling
Chapter 6 - Intro to Leveling Horizontal and Level Surfaces Datums Levels Level Rods Setting up the Level
Horizontal and Level Surfaces Vertical lines
Follow gravity Converge
Datum – reference at known distance from center of gravity
Elevation – vertical distance above datum
Level surface connects points of equal elevation
Horizontal is perpendicular to Vertical
Datum Elevations Sea level
NGVD 1929 NAVD 1988
“Above flood stage” Fargo – height over one of the dams Harwood - NAVD
Assumed
Levels Dumpy Tilting Automatic Digital Laser
Dumpy Levels
Telescope Parts
ReticleCross-
hairsCapstan’s
screws
Focusing – Parallax Two focus
adjustments Objective Eyepiece
Both must focus on the reticle If not, image moves, or is out of focus
Focus eyepiece while sighting on a white piece of paper before sighting on target
Automatic Levels
Three-screw leveling foot
Compensator
Digital Levels Automatic level Level rod: barcode Push button:
Rod Reading Distance
Microprocessor Set reference Internal
Calculations
Laser Levels Low power Types
Spinner Splitter Pipeline
Receiver Indicates Hi/Low Clamps to rod
Tied to Equipment
Level Rods
Feet: larger numbers, red
Tenths: black numbers
Hundredths: black bar, 0.01’ thick. Tops: even, Bottoms: odd
Feet: unknown
1/10ths: 0.1
1/100ths: .07
Read: X.17’
Level Rods
Engineer’s Rod,Read to 0.01’
Builder’s Rod,
Read to 1/8”
Reading the Rod
Fig. 6-11, pg 116
Setting up the Level Tripod set firmly in ground No plumb bob – point not needed Level the level screws
Pairs across Follow left thumb
Lock in place Check Level