SURVEYING CH 4

Question 1

is one of the fundamental measurements in surveying.

Answer 1

Distance

Question 2

Distance is required to…?

Answer 2

to give scale to a network of control points

to fix the position of topographic detail
by offsets or polar coordinates

to set out the position of a point
in constructon work

Question 3

The basic methods of measuring distance are

Answer 3

by taping or by electromagnetic distance measurement

Question 4

Methods for Making Linear/Horizontal Measurements

Answer 4

1. Pacing
2. Odometer readings
3. Tacheometry (stadia)
4. Subtense bar
5. Taping

Question 5

consists of counting the number of steps or paces in a
required distance.

Answer 5

Pacing

Question 6

defined as the length of a step in
walking. It may be measured from heel to heel or from toe to toe,

Answer 6

a pace

Question 7

means moving with measured steps

Answer 7

pacing

Question 8

A stride is equivalent to

Answer 8

two paces or a double step

Question 9

the length of
one’s pace

Answer 9

pace factor

Question 10

is defined as the procedure of obtaining
horizontal distances and difference in elevation based on the optical
geometry of the instrument

Answer 10

Tachymetry or tacheometry

Question 11

is a method of measuring distances rapidly with a telescope
(usually engineer’s transit or theodolite) and a graduated rod

Answer 11

stadia method

Question 12

is a 2 m long rounded steel tube through which runs a thin
invar.

Answer 12

subtense bar

Question 13

There are three fundamental sources of error in taping:

Answer 13

Instrumental errors

Natural errors

Personal errors

Question 14

a tape may differ in actual length from its nominal graduated
length because of a defect in manufacture or repair, or as a result of kinks.

Answer 14

Instrumental error

Question 15

the horizontal distance between end graduations of a tape varies
because of the effects of temperature, wind, and weight of the tape itself.

Answer 15

natural errors

Question 16

tape persons may be careless in setting pins, reading the tape, or
manipulating the equipment.

Answer 16

personal error

Question 17

can be one of the most important errors

Answer 17

incorrect length of tape

Question 18

types of tape correction

Answer 18

due to temperature
due to its own weight
due to tension

Question 19

is an instrument constant (usually equal to 100) which will depends on the spacing between stadia hairs.

Answer 19

Stadia interval factor

Question 20

is the apparent distance between the ponts on the rod where the upper and lower stadia hairs intersects the rod.

Answer 20

stadia intercept

Question 21

It is determined by subtracting the lower stadia hair reading from the upper stadia hair reading.

Answer 21

stadia intercept

Question 22

the distance from the center of the instrument to the principal focus.

Answer 22

stadia constant

Question 23

may be used for general use, where precision is not a prime consideration.

Answer 23

Linen or glass fiber tapes

Question 24

are standardized so that they measure their nominal flength at a designated temperature usually 20 °C and at a designated applied tension usually between 50 N to 80 N.

Answer 24

steel bands

Question 25

they have a negligible coefficient of expansion compared with steel, and hence temperature variations are not critical.

Answer 25

invar tapes

Question 26

is roughly, midway between steel and invar.

Answer 26

lovar tape

Question 27

are made of wood or steel, 2 m long and 25 mm in diameter, painted alternately red and white and have pointed metal shoes to allow them to be thrust into the ground. They are generally used to align a straight line between two points.

Answer 27

range poles

Question 28

made from No. 12 steel wire are also used to mark the tape lengths

Answer 28

chaining arrows

Question 29

are generally used with roller-grips or tapeclamps to grip the tape firmly when the standard tension is applied.

Answer 29

spring balances

Question 30

are also necessary to record the tape temperature at the time of measurement, thereby permitting the computation of tape corrections when the temperature varies from standard.

Answer 30

field thermometer

Question 31

may be used to ensure that the tape is horizontal. This is basically a hand-held tube incorporating a spirit bubble to ensure a horizontal line of sight.

Answer 31

hand levels

Question 32

may be necessary if stepped taping is used.

Answer 32

plumb bobs

Question 33

are necessary in rough ground, to afford a mark against which the tape may be read.

Answer 33

measuring plates

Question 34

is the process of breaking the overall distance down into manageable short sections, each much less than a whole tape length.

Answer 34

step measurement