Civil engineering

1. Lect#4
Linear and
angular
Measurement
By. M.Z jamali

2. Linear measurement
• Measurement in which horizontal or vertical
distance between two points is measured is
called linear measurement.

3. Methods of Linear
measurement
• Pacing (earlier age)
• Pedometer
• Passometer
• Permbulator
• Odometer
• Chain
• Tape

4. Pacing/stepping
• For rough and speedy work ,
distances are measured by pacing.,
i.e by counting numbers of steps
taken by a man from one point to
other.
• A walking space of man is
considered 2.5ft or 80cm.
• This is earlier age method and
now days it is generally used in
reconnaissance survey.

5. Passometer
• Passometer is a pocket instrument which
count the number of paces taken by a
person carrying it.
• It automatically records the number of
paces. Its mechanism is being operated by
the motion of the body.
• It should be held vertically in pocket.

6. Pedometer
• Pedometer The device which
count steps and measure the
distance automatically is known
as pedometer.
• It is similar to passometer but
difference is that passometer
count the number of paces
whereas pedometer records the
distance.
• It is adjusted according to
the length of the pace of the
person carrying it.

7. Perambulator

8. Perambulator
• Perambulator
The instrument provided with single wheel
with forks and handle to measure the
distance between two points is known as
perambulator.
• The instrument is wheeled along the line the
length of which is desired.
• The distance traverse is
automatically registered on the dials.

9. Odometer
• Odometer
• The device which attached with the wheel of
any vehicle and records the number of
revolutions of the wheel is known as
odometer.
• The number of revolutions multiplied by the
circumference of the wheel and records the
distance.

10. Chain

11. Chain
• Metric chain
• Günter’s Chain
• Revenue Chain
• Engineers chain
• For taking readings chain are provided tallies
after 10-15 links.
• By counting theses tallies distance can be
determined.
• For Ordinary work (less Precision) Chain is used.

12. Metric chain
• These chains are made in lengths of 20 and
30 meters.
• 20 m chain is divided in 100links and 30 m
chain in 150 liks. Length of each link is 0.2
m in both chains.
• To facilitate reading of measurement tallies
are provided in a 20 m chain after 10
links(2 m) and after 25 links(5m) in 30 m
chain.
• Suitable for fairly level ground.

13. • c. Günter’s Chain:
• It is 66 ft long and is divided into 100 links.
Each link is 0.66 ft long.
• It is very convenient for measuring distance
in miles and furlongs. Also for measuring
area and when the units of area is an acre.
• Revenue Chain:
• It is commonly used for measuring fields in
cadastral survey. It is 33 ft long and divided
into 16 links. Each link is 2.0625 ft long

14. • . Engineer’s chain:
• It is 100 ft long and it is divided into 100
links. Each link is 1 ft in a length. Used in all
Engineering surveys.

15. Engineer Chain
’

16. Revenue Chain

17. Tape

18. Cloth tape
• It is 15mm wide and is
available in length of
10m and 15m.
• This is generally used in
measuring offset and
ordinary works.

19. • Invar tape: Made of steel 64% and nickel 36%,
available in size 30m, 50m, and 100 m. having
lower co-efficient of expansion 0.00000012
per degree Celsius. Used for high degree of
precision required for base measurements.

20. • Metallic Tape
• More Durable
• Available in lengths of 15,20, and
30m. Used for all survey work.
• Steel tape. Available in length10,
15, 20, 30 and 50 meters.
• For Great Accuracy Steel Tape is
used

22. Angular Measurement.
• The measurement in which angle between
two lines and direction of two lines is
measured is called angular measurement.

23. Instrument used in Angular
Measurement
• Compass.
• Clinometers
• T-Square

24. Clinometer
• An instrument used for measuring the angle
or elevation of slopes

25. Clinometer

26. Compass
• A compass is a small instrument
essentially consisting of a
graduated circle, and a line of
sight.
• The compass can not measures
angle between two lines directly
but can measure angle of a line
with reference to magnetic
meridian at the instrument station
point is called magnetic bearing
of a line.

27. Set Square
• Used to measure
only 90 degree
angle

28. Modern Techniques/
instrument
• EDM ( Electronic Distance Machine)
• Tacheometer
• Level Machine
• Theodolite
• Total Station

29. EDM.
Electronic distance measuring instrument
is a surveying instrument for measuring
horizontal distance electronically between
two points.
This is mainly done by chaining or taping.
It is a rapid method

30. Tacheometer

31. Tacheometer
• Tacheometer by which the positions, both
horizontal and vertical, of points on the earth's
surface relatively to one another are determined
without using a chain or tape or a separate
leveling instrument.
• The ordinary methods of surveying with a
Theodolite, chain, and leveling instrument are
fairly satisfactory when the ground is pretty
clear of obstructions and not very precipitous,
but it becomes extremely difficult when the
ground is much covered with bush, or broken up
by ravines

32. Level Machine

33. Level Machine
• A dumpy level/ automatic
level is an optical
instrument used to establish
or verify points in the same
horizontal plane. It is used
in surveying and building wi
th a vertical staff to
measure height differences
and to transfer, measure
and set heights.

34. Theodolite

35. Theodolite
• Theodolite is an instrument used in
surveying to measure horizontal and vertical
angles. The line of sight of Theodolite can be
rotated through 180o in vertical plane about
its horizontal axis.
• Theodolite which can be rotated through
180o in vertical plane about its horizontal
axis is called Transit Theodolite and Non-
Transit if rotation is not possible

36. Total Station :-

37. Total Station :-
• A total station is an electronic/optical instrument
used in modern surveying
• Total station is an equipment combination
of Electromagnetic Distance Measuring
Instrument and electronic Theodolite.
• It is also integrated with microprocessor, electronic
data collector and storage system. The instrument
can be used to measure horizontal and vertical
angles as well as horizontal, vertical and sloping
distance of object to the instrument.

38. Prisim

39. Ranging Rod

40. Staff rod