Page 35 - 4798

Sources of Errors in Taping
There are three fundamental sources of errors in taping.
Instrumental errors: A tape may differ in actual length from its nominal
graduation and length because of defects in manufacturing or repair.
Nominal errors: The horizontal distance between end graduations of a tape
varies because of the effects of temperature, wind and weight of the tape itself.
Personal errors: Tape persons may be careless in setting pins, reading tapes, or
manipulating the equipment.

Systematic Errors in Taping
Systematic errors in taping linear distances are those attributable to the
following causes
 The tape is not of standard length
 The tape is not horizontal
 Variation in temperature
 Variation in tension
 Incorrect alignment of tape
 The tape is not straight

Exercise
1. For the following data, compute the horizontal distance for a recorded slope
distance AB
0
(a). AB = 327.28 m, slope angle = 4 15'
(b). AB = 382.96 m, difference in elevation A to B = 18.3 m
2. A triangular piece of land is bounded by 42.5 m of fencing on one side,
51.2m of stonewall on another side, and 85.7 of road frontage on the third side.
What are the interior angles formed by the boundary lines?
3. Two points on the opposite sides of a lake, D and E, are 355.5 and 276.2 ft,
respectively, from the third point, F, on the shore. The lines joining points D and E
0
with point F intersect at an angle of 71 45’. What is the distance DE?

33