LECTURE 4 Flashcards
Direct measurement of distances with steel tapes
Taping
In gunter’s chain, 100 links is equivalent to how many feet?
66 ft
what are the taping accessories
- Range Pole
- Chaining pins
- Tension Handle
- Plumb bob
- Wooden Stake
- Leather thong
- Clinometer
marked with alternate 1-ft long red
and white bands that can be used
for rough measurements
range pole
used to mark tape lengths
chaining pins
are made of number 12 steel wire,
sharply pointed at one end, have a
round loop at the other end, and are
painted with alternate red and white
bands
chaining pins
used to mark direction
of exact point
plumb bob
Being used as markers especially in
soft soil-based environment
wooden stake
measuring elevation angles above horizontal
clinometer
what are the taping operations
- Breaking Tape
- Slope Taping
Measurement of shorter distances which are accumulated to total a full tape length
Breaking tape
Taped measurements are made directly along the slopes when the ground is of uniform inclination
Slope taping
Rules in tape correction
> Measured
- too long: add
- too short: subtract
> Laid out
- too long: subtract
- too short: add
What are the corrections to tape
- Tape Not of Standard Length
- Slope
- Alignment
- Temperature
- Tension
- Sag
- Wind
Often due to imperfections in their
manufacture, stretching or wear
Tape not of standard length
Linear error due to inaccuracy in alignment
of a tape
due to alignment
Occurs when measurements are taken above or below the standard temperature of the tape
due to temperature
Arises whenever the pull applied is different from the standard
due to tension
Occurs when tape supports
are only at its ends or at the
2 points measured
due to sag
Caused by a force perpendicular to the direction of taping
due to wind
