2. Outcomes:
You will have knowledge about Surveying and
Surveying’s Intruments that are used in fields.
You will learn different new terminologies about
surveying.
This lecture would also help you for objective oriented
study.
You will have to memorize some constants.
3. Define Surveying?
The art of determining the relative
positions of different objects on the
surface of earth or beneath the
surface of earth, by measuring the
horizontal distances between them
,and by preparing a map to any
suitable scale is called surveying.
4. Introduction to various
Surveying Instruments:
In Surveying, we measure horizontal
distances, horizontal angels, vertical
angles, levels and etc.
5. Surveying Instruments 5
Different type of instruments used in surveying are
• Chain
Chain is an instrument used to measure linear distance in
surveying.
6.
7.
8. Chains
The chain is composed of 100 or 150 pieces of steel /iron
which are also called links. The ends of each link are bent
into a loop and connected together by means of three oval
rings which give flexibility to the chain. The joints of the
links are usually open, but in the best chains they are mostly
welded.
The ends of the chain are provided with brass handless for
dragging the chain on the ground, so that the chain can be
turned round without twisting. The out side of the handle is
the zero point or the end point of the chain and the length
of the chain is measured from the out side of the one
handle to the out side of the other. The length of the link
is the distance between the centers of the two consecutive
/ continuous middle rings.
9. Types of Chain
Gunter’s Chain/Suveyor’s Chain
It is 22 yards or 66 feet long and is divided into 100 links; the
length of each link is 0.66 feet or 7.92 inches. Formerly it
was mainly used in land surveying. It is very convenient
for measuring distances in miles and furlongs and for
measuring land when the unit of area is an acre on
account of its simple relation to the mile and acre.
10 Gunter’s chain = 01 furlong
1 furlong= 660ft
80 Gunter’s chain = 01 mile
10 Square Gunter’s chain = 01 acre
10. Revenue chain:
This chain is commonly used for measuring fields in
cadastral survey. It is 33 feet long and is divided into
16 links and each link is 2.0625 feet long.
Engineering or Engineer’s Chain:
The engineering chain is 100 feet long and is divided
into 100 links; each link is 01 feet long. It is used in all
engineering surveys. When long links are measured, it is
more accurate than the Gunter’s chain, because of its
greater length. The distances measured with the
engineer’s chain are recorded in feet and decimals.
11. Metric Chain:
Those countries in which the meter is the unit of
length, chains of 10, 20 and 30 meters are commonly
used. The 20-meter chain which is in most common
chain use is divided into 100 links.
30 meter chain into 150 links
Each link 20 cm
In 1 meter =5 links
12. Tapes
Accurate measurements are carried out through tape in
survey.
Lighter in weight.
Easier to handle than chain
Types
Cloth or linen tape
Invar tape( Metallic-nickel)
Steel tape(Cloth wire)
Fiberglass tape
15. • Staff rod/ Levelling rods
Used with auto level in measuring the levels of different points or objects.
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16. • Ranging Rods
These rods are used in surveying for stationing and ranging of
lines.
For Ranging atleast 3 rods
• Reflector/Prism
Used in total station
Surveying as shown
in figure
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17. • Compass
A compass is an instrument used for navigation and orientation
that shows direction relative to the geographic "cardinal directions
i.e. (North, South, East and West)", or "points".
Compass are of different types.
1. Trough Compass
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18. 2. Prismatic Compass
This Prismatic Compass is used for the purpose of measuring
magnetic bearings.
-whole circle bearings.
-0 degree on south pole.
-0 to 360 degrees
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19. Surveyor Compass
This compass is also used fro measuring bearing with the
North and south poles. The bearing are shown in quadrants.
For Reduced Bearings.
0-90 degrees
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20. Optical Square
A small hand instrument used by
surveyors for laying off a right angle by
means of two mirrors set at an angle of
45 degrees.
21. Abney level
A kind of clinometer
consisting of a sighting tube,
spirit level, and graduated
scale.
22. • Planimeter
The Planimeter is a drafting instrument used to measure the area of
a graphically represented planar region. The region being measured
may have any irregular shape, making this instrument remarkably
versatile.
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23. • Bags
Used for keeping the instruments
like prism etc. safe.
• Field Book
Used for entering the
field data (measurements).
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25. • Theodolite
Used for measuring horizontal
and vertical angles.
Most precise instrument.
Accuracy upto 10-20 seconds
• Total Station
Used for measuring angles,
Coordinates, levelling etc.
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26. • Tripod
Used for setting out of Instruments like Auto level, theodolite,
total stations etc.
• Pegs
Used for stations point or
used in setting of curves.
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30. Instruments for measuring
horizontal distances:
Passometer:
An instrument, shaped like a
watch that is used to count
the number of a person's
steps.
Pedometer:
An instrument for estimating
the distance travelled on foot
by recording the number of
steps taken.
31. Odometer
An instrument for
measuring the distance
travelled by a wheeled
vehicle.
Perambulator
A surveyor's wheel, also
called a clickwheel,
hodometer, waywiser,
trundle wheel, measuring
wheel or perambulator is
a device for measuring
distance.
32. Extra Instruments.
Line ranger
Cross Staff
Alidade
Sextant
French Cross Staff
Geodimeter
Fathometer
Ghat Tracer
Substense Bar
Tellurometer
Gradiometer.
Tachometer